/*************************************************************************************************************
 The MIT License

 Copyright (C) 2006-2019 David Dubbeldam, Sofia Calero, Thijs Vlugt, Donald E. Ellis, and Randall Q. Snurr.

     D.Dubbeldam@uva.nl            http://www.uva.nl/profiel/d/u/d.dubbeldam/d.dubbeldam.html
     scaldia@upo.es                http://www.upo.es/raspa/
     t.j.h.vlugt@tudelft.nl        http://homepage.tudelft.nl/v9k6y
     don-ellis@northwestern.edu    http://dvworld.northwestern.edu/
     snurr@northwestern.edu        http://zeolites.cqe.northwestern.edu/

 Permission is hereby granted, free of charge, to any person
 obtaining a copy of this software and associated documentation
 files (the "Software"), to deal in the Software without
 restriction, including without limitation the rights to use,
 copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the
 Software is furnished to do so, subject to the following
 conditions:

 The above copyright notice and this permission notice shall be
 included in all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 OTHER DEALINGS IN THE SOFTWARE.
**************************************************************************************************************/

#include <stdlib.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <sys/stat.h>
#include "potentials.h"
#include "molecule.h"
#include "framework.h"
#include "framework_energy.h"
#include "framework_force.h"
#include "framework_hessian.h"
#include "simulation.h"
#include "integration.h"
#include "cbmc.h"
#include "ewald.h"
#include "utils.h"
#include "grids.h"
#include "output.h"
#include "grids.h"
#include "movies.h"
#include "warnings.h"

// For a framework that is kept rigid it is effecient to precompute the energy and forces.
// The amount of points is compute from
//   (a) option 'SpacingVDWGrid 0.15' for Van der Waal grids
//   (b) option 'SpacingCoulombGrid 0.15' for the electrostatic grid
// 0.15 Angstrom per point seems to be a good value
// the sizes of the grids can be large, so due to memory-restrictions the amount and type of pseudo-atoms to
// be precomputed needs to chosen with care.

// for 2D bicubic interpolation, see Numerical Recipes 3.6 Interpolation in more dimensions
// the code here is the extension to 3D using the transformation matrix of Lekien and Marsden
//   F. Lakien and J. Marsden, "Tricubic interpolation in three dimensions"
//   International Journal for Numerical Methods in Engineering, 63, 455-471, 2005
//
// The algorithme is a local tricubic interpolation scheme in three dimensions that is both C^1 and isotropic. It uses
// a 64x64 matrix that gives the relationship between the derivatives at the corners of the elements and the coefficients of
// the trcubic interpolant for this element.
// The problem is *not* separated into 3 three-dimensional problems. This allows for a much easier and accurate computation of
// higher derivatives, e.g. the force, of the extrapolated field.
//
// Grids for triclinic frameowrks are based on a enclosing rectangular box. The tricubic interpolation algorithm operates
// on a unit cube. Notice that the derivatives are given in terms of the unit cube and must be divided by the actual size
// of the elements.

static int Coeff[64][64] = {
{  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{ -3,  3,  0,  0,  0,  0,  0,  0, -2, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  2, -2,  0,  0,  0,  0,  0,  0,  1,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 , 0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -3,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -2, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  2, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   1,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{ -3,  0,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0, -3,  0,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -2,  0, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  9, -9, -9,  9,  0,  0,  0,  0,  6,  3, -6, -3,  0,  0,  0,  0,  6, -6,  3, -3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   4,  2,  2,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{ -6,  6,  6, -6,  0,  0,  0,  0, -3, -3,  3,  3,  0,  0,  0,  0, -4,  4, -2,  2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -2, -2, -1, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  2,  0, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  2,  0, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   1,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{ -6,  6,  6, -6,  0,  0,  0,  0, -4, -2,  4,  2,  0,  0,  0,  0, -3,  3, -3,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -2, -1, -2, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  4, -4, -4,  4,  0,  0,  0,  0,  2,  2, -2, -2,  0,  0,  0,  0,  2, -2,  2, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   1,  1,  1,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -3,  3,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0, -2, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  2, -2,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -3,  3,  0,  0,  0,  0,  0,  0, -2, -1,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  2, -2,  0,  0,  0,  0,  0,  0,  1,  1,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -3,  0,  3,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0, -3,  0,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0, -1,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  9, -9, -9,  9,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  6,  3, -6, -3,  0,  0,  0,  0,  6, -6,  3, -3,  0,  0,  0,  0,  4,  2,  2,  1,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -6,  6,  6, -6,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0, -3, -3,  3,  3,  0,  0,  0,  0, -4,  4, -2,  2,  0,  0,  0,  0, -2, -2, -1, -1,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  2,  0, -2,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  2,  0, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  1,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -6,  6,  6, -6,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0, -4, -2,  4,  2,  0,  0,  0,  0, -3,  3, -3,  3,  0,  0,  0,  0, -2, -1, -2, -1,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  4, -4, -4,  4,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  2,  2, -2, -2,  0,  0,  0,  0,  2, -2,  2, -2,  0,  0,  0,  0,  1,  1,  1,  1,  0,  0,  0,  0},
{ -3,  0,  0,  0,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0,  0,  0, -1,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0, -3,  0,  0,  0,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0, -2,  0,  0,  0, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  9, -9,  0,  0, -9,  9,  0,  0,  6,  3,  0,  0, -6, -3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  6, -6,  0,  0,  3, -3,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  4,  2,  0,  0,  2,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{ -6,  6,  0,  0,  6, -6,  0,  0, -3, -3,  0,  0,  3,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -4,  4,  0,  0, -2,  2,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0, -2, -2,  0,  0, -1, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -3,  0,  0,  0,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0,  0,  0, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -3,  0,  0,  0,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0,  0,  0, -1,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  9, -9,  0,  0, -9,  9,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   6,  3,  0,  0, -6, -3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  6, -6,  0,  0,  3, -3,  0,  0,  4,  2,  0,  0,  2,  1,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -6,  6,  0,  0,  6, -6,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -3, -3,  0,  0,  3,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -4,  4,  0,  0, -2,  2,  0,  0, -2, -2,  0,  0, -1, -1,  0,  0},
{  9,  0, -9,  0, -9,  0,  9,  0,  0,  0,  0,  0,  0,  0,  0,  0,  6,  0,  3,  0, -6,  0, -3,  0,  6,  0, -6,  0,  3,  0, -3,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  4,  0,  2,  0,  2,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  9,  0, -9,  0, -9,  0,  9,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   6,  0,  3,  0, -6,  0, -3,  0,  6,  0, -6,  0,  3,  0, -3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  4,  0,  2,  0,  2,  0,  1,  0},
{-27, 27, 27,-27, 27,-27,-27, 27,-18, -9, 18,  9, 18,  9,-18, -9,-18, 18, -9,  9, 18,-18,  9, -9,-18, 18, 18,-18, -9,  9,  9, -9,
 -12, -6, -6, -3, 12,  6,  6,  3,-12, -6, 12,  6, -6, -3,  6,  3,-12, 12, -6,  6, -6,  6, -3,  3, -8, -4, -4, -2, -4, -2, -2, -1},
{ 18,-18,-18, 18,-18, 18, 18,-18,  9,  9, -9, -9, -9, -9,  9,  9, 12,-12,  6, -6,-12, 12, -6,  6, 12,-12,-12, 12,  6, -6, -6,  6,
   6,  6 , 3,  3, -6, -6, -3, -3,  6,  6, -6, -6,  3,  3, -3, -3,  8, -8,  4, -4,  4, -4,  2, -2,  4,  4,  2,  2,  2,  2,  1,  1},
{ -6,  0,  6,  0,  6,  0, -6,  0,  0,  0,  0,  0,  0,  0,  0,  0, -3,  0, -3,  0,  3,  0,  3,  0, -4,  0,  4,  0, -2,  0,  2,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0, -2,  0, -1,  0, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0, -6,  0,  6,  0,  6,  0, -6,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -3,  0, -3,  0,  3,  0,  3,  0, -4,  0,  4,  0, -2,  0,  2,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0, -2,  0, -1,  0, -1,  0},
{ 18,-18,-18, 18,-18, 18, 18,-18, 12,  6,-12, -6,-12, -6, 12,  6,  9, -9,  9, -9, -9,  9, -9,  9, 12,-12,-12, 12,  6, -6, -6,  6,
   6,  3,  6,  3, -6, -3, -6, -3,  8,  4, -8, -4,  4,  2, -4, -2,  6, -6,  6, -6,  3, -3,  3, -3,  4,  2,  4,  2,  2,  1,  2,  1},
{-12, 12, 12,-12, 12,-12,-12, 12, -6, -6,  6,  6,  6,  6, -6, -6, -6,  6, -6,  6,  6, -6,  6, -6, -8,  8,  8, -8, -4,  4,  4, -4,
  -3, -3, -3, -3,  3,  3,  3,  3, -4, -4,  4,  4, -2, -2,  2,  2, -4,  4, -4,  4, -2,  2, -2,  2, -2, -2, -2, -2, -1, -1, -1, -1},
{  2,  0,  0,  0, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  1,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  2,  0,  0,  0, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{ -6,  6,  0,  0,  6, -6,  0,  0, -4, -2,  0,  0,  4,  2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -3,  3,  0,  0, -3,  3,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0, -2, -1,  0,  0, -2, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  4, -4,  0,  0, -4,  4,  0,  0,  2,  2,  0,  0, -2, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  2, -2,  0,  0,  2, -2,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  0,  0,  1,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  2,  0,  0,  0, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   2,  0,  0,  0, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  1,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -6,  6,  0,  0,  6, -6,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -4, -2,  0,  0,  4,  2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -3,  3,  0,  0, -3,  3,  0,  0, -2, -1,  0,  0, -2, -1,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  4, -4,  0,  0, -4,  4,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   2,  2,  0,  0, -2, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  2, -2,  0,  0,  2, -2,  0,  0,  1,  1,  0,  0,  1,  1,  0,  0},
{ -6,  0,  6,  0,  6,  0, -6,  0,  0,  0,  0,  0,  0,  0,  0,  0, -4,  0, -2,  0,  4,  0,  2,  0, -3,  0,  3,  0, -3,  0,  3,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0, -1,  0, -2,  0, -1,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0, -6,  0,  6,  0,  6,  0, -6,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  -4,  0, -2,  0,  4,  0,  2,  0, -3,  0,  3,  0, -3,  0,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0, -2,  0, -1,  0, -2,  0, -1,  0},
{ 18,-18,-18, 18,-18, 18, 18,-18, 12,  6,-12, -6,-12, -6, 12,  6, 12,-12,  6, -6,-12, 12, -6,  6,  9, -9, -9,  9,  9, -9, -9,  9,
   8,  4,  4,  2, -8, -4, -4, -2,  6,  3, -6, -3,  6,  3, -6, -3,  6, -6,  3, -3,  6, -6,  3, -3,  4,  2,  2,  1,  4,  2,  2,  1},
{-12, 12, 12,-12, 12,-12,-12, 12, -6, -6,  6,  6,  6,  6, -6, -6, -8,  8, -4,  4,  8, -8,  4, -4, -6,  6,  6, -6, -6,  6,  6, -6,
  -4, -4, -2, -2 , 4,  4,  2,  2, -3, -3,  3,  3, -3, -3,  3 , 3, -4,  4, -2,  2, -4,  4, -2,  2, -2, -2, -1, -1, -2, -2, -1, -1},
{  4,  0, -4,  0, -4,  0,  4,  0,  0,  0,  0,  0,  0,  0,  0,  0,  2,  0,  2,  0, -2,  0, -2,  0,  2,  0, -2,  0,  2,  0, -2,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  1,  0,  1,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0},
{  0,  0,  0,  0,  0,  0,  0,  0,  4,  0, -4,  0, -4,  0,  4,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   2,  0,  2,  0, -2,  0, -2,  0,  2,  0, -2,  0,  2,  0, -2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  1,  0,  1,  0,  1,  0},
{-12, 12, 12,-12, 12,-12,-12, 12, -8, -4,  8,  4,  8,  4, -8, -4, -6,  6, -6,  6,  6, -6,  6, -6, -6,  6,  6, -6, -6,  6,  6, -6,
  -4, -2, -4, -2,  4,  2,  4,  2, -4, -2,  4,  2, -4, -2,  4,  2, -3,  3, -3,  3, -3,  3, -3,  3, -2, -1, -2, -1, -2, -1, -2, -1},
{  8, -8, -8,  8, -8,  8,  8, -8,  4,  4, -4, -4, -4, -4,  4,  4,  4, -4,  4, -4, -4,  4, -4,  4,  4, -4, -4,  4,  4, -4, -4,  4,
   2,  2,  2,  2, -2, -2, -2, -2,  2,  2, -2, -2,  2,  2, -2, -2,  2, -2,  2, -2,  2, -2,  2, -2,  1,  1,  1,  1,  1,  1,  1,  1}};

extern bool STREAM;

int UseTabularGrid;
REAL SpacingVDWGrid;
REAL SpacingCoulombGrid;

int NumberOfGrids;

float *****VDWGrid;
float ****CoulombGrid;

INT_VECTOR3 NumberOfVDWGridPoints;
static INT_VECTOR3 NumberOfCoulombGridPoints;
static VECTOR SizeGrid;
static VECTOR ShiftGrid;
static VECTOR DeltaVDWGrid;
static VECTOR DeltaCoulombGrid;
int *GridTypeList;
char (*GridTypeListName)[256];

// Blocking variables
static char ***BlockingGrid;
int BlockEnergyGrids;
int BlockGridPockets;
int BlockGridPores;
REAL BlockEnergyGridOverlapCriteria;
int NumberOfGridSeeds;
VECTOR *GridSeeds;

static INT_VECTOR3 *Queue;
static int QueueSize;

VECTOR MapToUnitCell(VECTOR pos)
{
  VECTOR s;

  switch(BoundaryCondition[CurrentSystem])
  {
    case CUBIC:
    case RECTANGULAR:
      pos.x-=UnitCellSize[CurrentSystem].x*(REAL)(NINT(pos.x/UnitCellSize[CurrentSystem].x));
      pos.y-=UnitCellSize[CurrentSystem].y*(REAL)(NINT(pos.y/UnitCellSize[CurrentSystem].y));
      pos.z-=UnitCellSize[CurrentSystem].z*((REAL)NINT(pos.z/UnitCellSize[CurrentSystem].z));
      if(pos.x<0.0) pos.x+=UnitCellSize[CurrentSystem].x;
      if(pos.y<0.0) pos.y+=UnitCellSize[CurrentSystem].y;
      if(pos.z<0.0) pos.z+=UnitCellSize[CurrentSystem].z;
      break;
    case TRICLINIC:
      s.x=InverseUnitCellBox[CurrentSystem].ax*pos.x+InverseUnitCellBox[CurrentSystem].bx*pos.y+InverseUnitCellBox[CurrentSystem].cx*pos.z;
      s.y=InverseUnitCellBox[CurrentSystem].ay*pos.x+InverseUnitCellBox[CurrentSystem].by*pos.y+InverseUnitCellBox[CurrentSystem].cy*pos.z;
      s.z=InverseUnitCellBox[CurrentSystem].az*pos.x+InverseUnitCellBox[CurrentSystem].bz*pos.y+InverseUnitCellBox[CurrentSystem].cz*pos.z;
      // apply boundary condition
      s.x-=(REAL)NINT(s.x);
      s.y-=(REAL)NINT(s.y);
      s.z-=(REAL)NINT(s.z);
      if(s.x<0.0) s.x+=1.0;
      if(s.y<0.0) s.y+=1.0;
      if(s.z<0.0) s.z+=1.0;
      pos.x=UnitCellBox[CurrentSystem].ax*s.x+UnitCellBox[CurrentSystem].bx*s.y+UnitCellBox[CurrentSystem].cx*s.z;
      pos.y=UnitCellBox[CurrentSystem].ay*s.x+UnitCellBox[CurrentSystem].by*s.y+UnitCellBox[CurrentSystem].cy*s.z;
      pos.z=UnitCellBox[CurrentSystem].az*s.x+UnitCellBox[CurrentSystem].bz*s.y+UnitCellBox[CurrentSystem].cz*s.z;
      break;
  }
  return pos;
}

int CheckIfPointIsInUnitCell(VECTOR pos)
{
  VECTOR s;

  s.x=InverseUnitCellBox[CurrentSystem].ax*pos.x+InverseUnitCellBox[CurrentSystem].bx*pos.y+InverseUnitCellBox[CurrentSystem].cx*pos.z;
  s.y=InverseUnitCellBox[CurrentSystem].ay*pos.x+InverseUnitCellBox[CurrentSystem].by*pos.y+InverseUnitCellBox[CurrentSystem].cy*pos.z;
  s.z=InverseUnitCellBox[CurrentSystem].az*pos.x+InverseUnitCellBox[CurrentSystem].bz*pos.y+InverseUnitCellBox[CurrentSystem].cz*pos.z;

  if(s.x<0.0) return FALSE;
  if(s.y<0.0) return FALSE;
  if(s.z<0.0) return FALSE;
  if(s.x>=1.0) return FALSE;
  if(s.y>=1.0) return FALSE;
  if(s.z>=1.0) return FALSE;
  return TRUE;
}

VECTOR MapZToBox(VECTOR pos)
{
  pos.z-=Box[0].cz*NINT(pos.z/Box[0].cz);
  if(pos.z<0.0) pos.z+=Box[0].cz;
  return pos;
}

void MakeASCIGrid(void)
{
  int i,j,k,l,typeA,save;
  REAL percent,teller,TailEnergy;
  POINT pos;
  REAL value,third_derivative;
  VECTOR first_derivative;
  REAL_MATRIX3x3 second_derivative;
  char buffer[1024];
  FILE *FilePtr;

  if (STREAM)
  {
    fprintf(stderr, "Streaming not yet supported for this function.");
    exit(0);
  }

  CurrentSystem=0;
  if(MIN3(BoxProperties[CurrentSystem].cx,BoxProperties[CurrentSystem].cy,
          BoxProperties[CurrentSystem].cz)<CutOffVDW)
  {
     fprintf(stderr, "ERROR:  Cutoff smaller than half of one of the perpendicular boxlengths !!!\n");
     fprintf(stderr, "        (Cutoff: %lf perpendicular boxlengths: %lf %lf %lf)\n",(double)CutOffVDW,
             (double)BoxProperties[CurrentSystem].cx,(double)BoxProperties[CurrentSystem].cy,(double)BoxProperties[CurrentSystem].cz);
     fprintf(stderr, "Advice: choose more unitcells for constructing the grid.\n");
     exit(0);
  }

  NumberOfAdsorbateMolecules[CurrentSystem]=0;
  NumberOfCationMolecules[CurrentSystem]=0;

  CalculateForce();
  TailEnergy=UTailCorrection[CurrentSystem];

  save=ChargeMethod;
  ChargeMethod=NONE;

  // compute the size of the grid and the shift of the origin of the enclosing box
  SizeGrid.x=SizeGrid.y=SizeGrid.z=0.0;
  ShiftGrid.x=ShiftGrid.y=ShiftGrid.z=0.0;

  SizeGrid.x+=fabs(UnitCellBox[CurrentSystem].ax);
  SizeGrid.y+=fabs(UnitCellBox[CurrentSystem].ay);
  SizeGrid.z+=fabs(UnitCellBox[CurrentSystem].az);
  if(UnitCellBox[CurrentSystem].ax<0.0) ShiftGrid.x+=UnitCellBox[CurrentSystem].ax;
  if(UnitCellBox[CurrentSystem].ay<0.0) ShiftGrid.y+=UnitCellBox[CurrentSystem].ay;
  if(UnitCellBox[CurrentSystem].az<0.0) ShiftGrid.z+=UnitCellBox[CurrentSystem].az;

  SizeGrid.x+=fabs(UnitCellBox[CurrentSystem].bx);
  SizeGrid.y+=fabs(UnitCellBox[CurrentSystem].by);
  SizeGrid.z+=fabs(UnitCellBox[CurrentSystem].bz);
  if(UnitCellBox[CurrentSystem].bx<0.0) ShiftGrid.x+=UnitCellBox[CurrentSystem].bx;
  if(UnitCellBox[CurrentSystem].by<0.0) ShiftGrid.y+=UnitCellBox[CurrentSystem].by;
  if(UnitCellBox[CurrentSystem].bz<0.0) ShiftGrid.z+=UnitCellBox[CurrentSystem].bz;

  SizeGrid.x+=fabs(UnitCellBox[CurrentSystem].cx);
  SizeGrid.y+=fabs(UnitCellBox[CurrentSystem].cy);
  SizeGrid.z+=fabs(UnitCellBox[CurrentSystem].cz);
  if(UnitCellBox[CurrentSystem].cx<0.0) ShiftGrid.x+=UnitCellBox[CurrentSystem].cx;
  if(UnitCellBox[CurrentSystem].cy<0.0) ShiftGrid.y+=UnitCellBox[CurrentSystem].cy;
  if(UnitCellBox[CurrentSystem].cz<0.0) ShiftGrid.z+=UnitCellBox[CurrentSystem].cz;

  // compute the number of grid points
  NumberOfVDWGridPoints.x=(int)(SizeGrid.x/SpacingVDWGrid);
  NumberOfVDWGridPoints.y=(int)(SizeGrid.y/SpacingVDWGrid);
  NumberOfVDWGridPoints.z=(int)(SizeGrid.z/SpacingVDWGrid);

  DeltaVDWGrid.x=SizeGrid.x/(REAL)NumberOfVDWGridPoints.x;
  DeltaVDWGrid.y=SizeGrid.y/(REAL)NumberOfVDWGridPoints.y;
  DeltaVDWGrid.z=SizeGrid.z/(REAL)NumberOfVDWGridPoints.z;

  fprintf(stderr, "ShiftGrid: %g %g %g\n",ShiftGrid.x,ShiftGrid.y,ShiftGrid.z);
  fprintf(stderr, "SizeGrid: %g %g %g\n",SizeGrid.x,SizeGrid.y,SizeGrid.z);
  fprintf(stderr, "Number of grid points: %d %d %d\n",NumberOfVDWGridPoints.x,NumberOfVDWGridPoints.y,NumberOfVDWGridPoints.z);

  percent=100.0/(REAL)((NumberOfVDWGridPoints.x+1)*NumberOfGrids);
  teller=0.0;

  fprintf(OutputFilePtr[CurrentSystem],"\n\n");
  fprintf(OutputFilePtr[CurrentSystem],"Generating an ASCI interpolation grid (%d x %d x %d)\n",NumberOfVDWGridPoints.x,NumberOfVDWGridPoints.y,NumberOfVDWGridPoints.z);
  fprintf(OutputFilePtr[CurrentSystem],"========================================================\n\n");
  fflush(OutputFilePtr[CurrentSystem]);

  mkdir("ASCI_Grids",S_IRWXU);

  for(l=0;l<NumberOfGrids;l++)
  {
    fprintf(OutputFilePtr[CurrentSystem],"Creating grid %d [%s]\n",l,PseudoAtoms[GridTypeList[l]].Name);
    fflush(OutputFilePtr[CurrentSystem]);

    sprintf(buffer,"ASCI_Grids/asci_grid_%s.grid",PseudoAtoms[GridTypeList[l]].Name);
    FilePtr=fopen(buffer,"w");

    typeA=GridTypeList[l];
    for(i=0;i<=NumberOfVDWGridPoints.x;i++)
    {
      teller=teller+1.0;
      for(j=0;j<=NumberOfVDWGridPoints.y;j++)
      {
        for(k=0;k<=NumberOfVDWGridPoints.z;k++)
        {
          switch(BoundaryCondition[CurrentSystem])
          {
            case CUBIC:
            case RECTANGULAR:
            case TRICLINIC:
            default:
              pos.x=i*SizeGrid.x/NumberOfVDWGridPoints.x+ShiftGrid.x;
              pos.y=j*SizeGrid.y/NumberOfVDWGridPoints.y+ShiftGrid.y;
              pos.z=k*SizeGrid.z/NumberOfVDWGridPoints.z+ShiftGrid.z;

              // apply boundary condition
              //value=CalculateFrameworkVDWEnergyAtPosition(pos,typeA);
              CalculateDerivativesAtPositionVDW(pos,typeA,&value,&first_derivative,&second_derivative,&third_derivative);
              break;
          }

          // cap the value
          if(value<EnergyOverlapCriteria)
            fprintf(FilePtr,"%g %g %g %g %g %g %g\n",pos.x,pos.y,pos.z,value*ENERGY_TO_KELVIN,
                    -first_derivative.x*ENERGY_TO_KELVIN,-first_derivative.y*ENERGY_TO_KELVIN,-first_derivative.z*ENERGY_TO_KELVIN);
          else
            fprintf(FilePtr,"%g %g %g %s %s %s %s\n",pos.x,pos.y,pos.z,"?","?","?","?");
        }
      }
      fprintf(OutputFilePtr[CurrentSystem],"Percentage finished                      : %d\n",(int)(teller*percent));
      fflush(OutputFilePtr[CurrentSystem]);
    }
    fclose(FilePtr);
  }
}


void MakeGrid(void)
{
  int i,j,k,l,tel2,typeA,save;
  REAL percent,teller,TailEnergy;
  POINT pos;
  REAL value,third_derivative;
  VECTOR first_derivative;
  REAL_MATRIX3x3 second_derivative;
  REAL smallest_r;

  if(MIN3(BoxProperties[CurrentSystem].cx,BoxProperties[CurrentSystem].cy,
          BoxProperties[CurrentSystem].cz)<CutOffVDW)
  {
     fprintf(stderr, "ERROR:  Cutoff smaller than half of one of the perpendicular boxlengths !!!\n");
     fprintf(stderr, "        (Cutoff: %lf perpendicular boxlengths: %lf %lf %lf)\n",(double)CutOffVDW,
             (double)BoxProperties[CurrentSystem].cx,(double)BoxProperties[CurrentSystem].cy,(double)BoxProperties[CurrentSystem].cz);
     fprintf(stderr, "Advice: choose more unitcells for constructing the grid.\n");
     exit(0);
  }

  NumberOfAdsorbateMolecules[CurrentSystem]=0;
  NumberOfCationMolecules[CurrentSystem]=0;

  CalculateForce();
  TailEnergy=UTailCorrection[CurrentSystem];

  save=ChargeMethod;
  ChargeMethod=NONE;

  // compute the size of the grid and the shift of the origin of the enclosing box
  SizeGrid.x=SizeGrid.y=SizeGrid.z=0.0;
  ShiftGrid.x=ShiftGrid.y=ShiftGrid.z=0.0;

  SizeGrid.x+=fabs(UnitCellBox[CurrentSystem].ax);
  SizeGrid.y+=fabs(UnitCellBox[CurrentSystem].ay);
  SizeGrid.z+=fabs(UnitCellBox[CurrentSystem].az);
  if(UnitCellBox[CurrentSystem].ax<0.0) ShiftGrid.x+=UnitCellBox[CurrentSystem].ax;
  if(UnitCellBox[CurrentSystem].ay<0.0) ShiftGrid.y+=UnitCellBox[CurrentSystem].ay;
  if(UnitCellBox[CurrentSystem].az<0.0) ShiftGrid.z+=UnitCellBox[CurrentSystem].az;

  SizeGrid.x+=fabs(UnitCellBox[CurrentSystem].bx);
  SizeGrid.y+=fabs(UnitCellBox[CurrentSystem].by);
  SizeGrid.z+=fabs(UnitCellBox[CurrentSystem].bz);
  if(UnitCellBox[CurrentSystem].bx<0.0) ShiftGrid.x+=UnitCellBox[CurrentSystem].bx;
  if(UnitCellBox[CurrentSystem].by<0.0) ShiftGrid.y+=UnitCellBox[CurrentSystem].by;
  if(UnitCellBox[CurrentSystem].bz<0.0) ShiftGrid.z+=UnitCellBox[CurrentSystem].bz;

  SizeGrid.x+=fabs(UnitCellBox[CurrentSystem].cx);
  SizeGrid.y+=fabs(UnitCellBox[CurrentSystem].cy);
  SizeGrid.z+=fabs(UnitCellBox[CurrentSystem].cz);
  if(UnitCellBox[CurrentSystem].cx<0.0) ShiftGrid.x+=UnitCellBox[CurrentSystem].cx;
  if(UnitCellBox[CurrentSystem].cy<0.0) ShiftGrid.y+=UnitCellBox[CurrentSystem].cy;
  if(UnitCellBox[CurrentSystem].cz<0.0) ShiftGrid.z+=UnitCellBox[CurrentSystem].cz;

  // compute the number of grid points
  NumberOfVDWGridPoints.x=(int)(SizeGrid.x/SpacingVDWGrid);
  NumberOfVDWGridPoints.y=(int)(SizeGrid.y/SpacingVDWGrid);
  NumberOfVDWGridPoints.z=(int)(SizeGrid.z/SpacingVDWGrid);

  if(NumberOfVDWGridPoints.x%2==0) NumberOfVDWGridPoints.x++;
  if(NumberOfVDWGridPoints.y%2==0) NumberOfVDWGridPoints.y++;
  if(NumberOfVDWGridPoints.z%2==0) NumberOfVDWGridPoints.z++;

  DeltaVDWGrid.x=SizeGrid.x/(REAL)NumberOfVDWGridPoints.x;
  DeltaVDWGrid.y=SizeGrid.y/(REAL)NumberOfVDWGridPoints.y;
  DeltaVDWGrid.z=SizeGrid.z/(REAL)NumberOfVDWGridPoints.z;

  fprintf(stderr, "ShiftGrid: %g %g %g\n",ShiftGrid.x,ShiftGrid.y,ShiftGrid.z);
  fprintf(stderr, "SizeGrid: %g %g %g\n",SizeGrid.x,SizeGrid.y,SizeGrid.z);
  fprintf(stderr, "Number of grid points: %d %d %d\n",NumberOfVDWGridPoints.x,NumberOfVDWGridPoints.y,NumberOfVDWGridPoints.z);

  percent=100.0/(REAL)((NumberOfVDWGridPoints.x+1)*NumberOfGrids);
  teller=0.0;
  tel2=1;

  fprintf(OutputFilePtr[CurrentSystem],"\n\n");
  fprintf(OutputFilePtr[CurrentSystem],"Generating an VDW interpolation grid (%d x %d x %d)\n",NumberOfVDWGridPoints.x,NumberOfVDWGridPoints.y,NumberOfVDWGridPoints.z);
  fprintf(OutputFilePtr[CurrentSystem],"========================================================\n\n");
  fflush(OutputFilePtr[CurrentSystem]);

  fprintf(stderr, "NumberOfGrids: %d\n",NumberOfGrids);
  for(l=0;l<NumberOfGrids;l++)
  {
    fprintf(OutputFilePtr[CurrentSystem],"Creating grid %d [%s]\n",l,PseudoAtoms[GridTypeList[l]].Name);
    fflush(OutputFilePtr[CurrentSystem]);

    // Allocate the memory for this grid
    VDWGrid[GridTypeList[l]]=(float****)calloc(NumberOfVDWGridPoints.x+1,sizeof(float***));
    for(i=0;i<=NumberOfVDWGridPoints.x;i++)
    {
      VDWGrid[GridTypeList[l]][i]=(float***)calloc(NumberOfVDWGridPoints.y+1,sizeof(float**));
      for(j=0;j<=NumberOfVDWGridPoints.y;j++)
      {
        VDWGrid[GridTypeList[l]][i][j]=(float**)calloc(NumberOfVDWGridPoints.z+1,sizeof(float*));
        for(k=0;k<=NumberOfVDWGridPoints.z;k++)
          VDWGrid[GridTypeList[l]][i][j][k]=(float*)calloc(8,sizeof(float));
      }
    }

    typeA=GridTypeList[l];
    for(i=0;i<=NumberOfVDWGridPoints.x;i++)
    {
      teller=teller+1.0;
      for(j=0;j<=NumberOfVDWGridPoints.y;j++)
      {
        for(k=0;k<=NumberOfVDWGridPoints.z;k++)
        {
          switch(BoundaryCondition[CurrentSystem])
          {
            case CUBIC:
            case RECTANGULAR:
            case TRICLINIC:
            default:
              pos.x=i*SizeGrid.x/NumberOfVDWGridPoints.x+ShiftGrid.x;
              pos.y=j*SizeGrid.y/NumberOfVDWGridPoints.y+ShiftGrid.y;
              pos.z=k*SizeGrid.z/NumberOfVDWGridPoints.z+ShiftGrid.z;

              // apply boundary condition
              CalculateDerivativesAtPositionVDW(pos,typeA,&value,&first_derivative,&second_derivative,&third_derivative);
              break;
          }

          // cap the value
          if(value>EnergyOverlapCriteria) 
          {
            value=2.0*EnergyOverlapCriteria;
            if(first_derivative.x>EnergyOverlapCriteria) first_derivative.x=EnergyOverlapCriteria;
            if(first_derivative.x<-EnergyOverlapCriteria) first_derivative.x=-EnergyOverlapCriteria;
            if(first_derivative.y>EnergyOverlapCriteria) first_derivative.y=EnergyOverlapCriteria;
            if(first_derivative.y<-EnergyOverlapCriteria) first_derivative.y=-EnergyOverlapCriteria;
            if(first_derivative.z>EnergyOverlapCriteria) first_derivative.z=EnergyOverlapCriteria;
            if(first_derivative.z<-EnergyOverlapCriteria) first_derivative.z=-EnergyOverlapCriteria;
            second_derivative.ax=second_derivative.bx=second_derivative.cx=0.0;
            second_derivative.ay=second_derivative.by=second_derivative.cy=0.0;
            second_derivative.az=second_derivative.bz=second_derivative.cz=0.0;
            third_derivative=0.0;
          }

          // store energy, and derivatives in "unit cube format"
          VDWGrid[GridTypeList[l]][i][j][k][0]=(float)value;
          VDWGrid[GridTypeList[l]][i][j][k][1]=(float)first_derivative.x*DeltaVDWGrid.x;
          VDWGrid[GridTypeList[l]][i][j][k][2]=(float)first_derivative.y*DeltaVDWGrid.y;
          VDWGrid[GridTypeList[l]][i][j][k][3]=(float)first_derivative.z*DeltaVDWGrid.z;
          VDWGrid[GridTypeList[l]][i][j][k][4]=(float)second_derivative.ay*(DeltaVDWGrid.x*DeltaVDWGrid.y);
          VDWGrid[GridTypeList[l]][i][j][k][5]=(float)second_derivative.az*(DeltaVDWGrid.x*DeltaVDWGrid.z);
          VDWGrid[GridTypeList[l]][i][j][k][6]=(float)second_derivative.bz*(DeltaVDWGrid.y*DeltaVDWGrid.z);
          VDWGrid[GridTypeList[l]][i][j][k][7]=(float)third_derivative*(DeltaVDWGrid.x*DeltaVDWGrid.y*DeltaVDWGrid.z);
        }
      }
      if((int)(teller*percent)>(int)((teller-1.0)*percent))
        fprintf(OutputFilePtr[CurrentSystem],"Percentage finished                      : %d\n",(int)(teller*percent));
      fflush(OutputFilePtr[CurrentSystem]);
    }
    fprintf(stderr, "Writing Grid\n");
    WriteVDWGrid(GridTypeList[l]);

    for(i=0;i<=NumberOfVDWGridPoints.x;i++)
    {
      for(j=0;j<=NumberOfVDWGridPoints.y;j++)
      {
        for(k=0;k<=NumberOfVDWGridPoints.z;k++)
        {
          free(VDWGrid[GridTypeList[l]][i][j][k]);
        }
        free(VDWGrid[GridTypeList[l]][i][j]);
      }
      free(VDWGrid[GridTypeList[l]][i]);
    }
    free(VDWGrid[GridTypeList[l]]);
  }

  // compute the number of grid points
  NumberOfCoulombGridPoints.x=(int)(SizeGrid.x/SpacingCoulombGrid);
  NumberOfCoulombGridPoints.y=(int)(SizeGrid.y/SpacingCoulombGrid);
  NumberOfCoulombGridPoints.z=(int)(SizeGrid.z/SpacingCoulombGrid);

  if(NumberOfCoulombGridPoints.x%2==0) NumberOfCoulombGridPoints.x++;
  if(NumberOfCoulombGridPoints.y%2==0) NumberOfCoulombGridPoints.y++;
  if(NumberOfCoulombGridPoints.z%2==0) NumberOfCoulombGridPoints.z++;

  DeltaCoulombGrid.x=SizeGrid.x/(REAL)NumberOfCoulombGridPoints.x;
  DeltaCoulombGrid.y=SizeGrid.y/(REAL)NumberOfCoulombGridPoints.y;
  DeltaCoulombGrid.z=SizeGrid.z/(REAL)NumberOfCoulombGridPoints.z;

  ChargeMethod=save;
  fprintf(OutputFilePtr[CurrentSystem],"\n\n");
  switch(ChargeMethod)
  {
    case EWALD:
      fprintf(OutputFilePtr[CurrentSystem],"Generating an Ewald-Coulomb interpolation grid (%d x %d x %d)\n",
              NumberOfCoulombGridPoints.x,NumberOfCoulombGridPoints.y,NumberOfCoulombGridPoints.z);
      break;
    case WOLFS_METHOD:
      fprintf(OutputFilePtr[CurrentSystem],"Generating an Coulomb interpolation grid using Wolf's method (%d x %d x %d)\n",
              NumberOfCoulombGridPoints.x,NumberOfCoulombGridPoints.y,NumberOfCoulombGridPoints.z);
      break;
    default:
      fprintf(stderr, "Skipping the Coulombic grid\n");
      exit(0);
      break;
  }
  fprintf(OutputFilePtr[CurrentSystem],"===============================================================\n\n");
  fflush(OutputFilePtr[CurrentSystem]);

  percent=100.0/(REAL)(NumberOfCoulombGridPoints.x+1);
  teller=0.0;

  // Allocate the memory for this grid
  CoulombGrid=(float****)calloc(NumberOfCoulombGridPoints.x+1,sizeof(float***));
  for(i=0;i<=NumberOfCoulombGridPoints.x;i++)
  {
    CoulombGrid[i]=(float***)calloc(NumberOfCoulombGridPoints.y+1,sizeof(float**));
    for(j=0;j<=NumberOfCoulombGridPoints.y;j++)
    {
      CoulombGrid[i][j]=(float**)calloc(NumberOfCoulombGridPoints.z+1,sizeof(float*));
      for(k=0;k<=NumberOfCoulombGridPoints.z;k++)
        CoulombGrid[i][j][k]=(float*)calloc(8,sizeof(float));
    }
  }

  typeA=ReturnPseudoAtomNumber("UNIT");
  for(i=0;i<=NumberOfCoulombGridPoints.x;i++)
  {
    teller=teller+1.0;
    for(j=0;j<=NumberOfCoulombGridPoints.y;j++)
    {
      for(k=0;k<=NumberOfCoulombGridPoints.z;k++)
      {
        switch(BoundaryCondition[CurrentSystem])
        {
          case CUBIC:
          case RECTANGULAR:
          case TRICLINIC:
          default:
            pos.x=i*SizeGrid.x/NumberOfCoulombGridPoints.x+ShiftGrid.x;
            pos.y=j*SizeGrid.y/NumberOfCoulombGridPoints.y+ShiftGrid.y;
            pos.z=k*SizeGrid.z/NumberOfCoulombGridPoints.z+ShiftGrid.z;
            smallest_r=CalculateDerivativesAtPositionReal(pos,typeA,&value,&first_derivative,&second_derivative,&third_derivative);
            break;
        }

        // cap the value
        if(value>EnergyOverlapCriteria||smallest_r<1.0)
        {
          value=2.0*EnergyOverlapCriteria;
          if(first_derivative.x>EnergyOverlapCriteria) first_derivative.x=EnergyOverlapCriteria;
          if(first_derivative.x<-EnergyOverlapCriteria) first_derivative.x=-EnergyOverlapCriteria;
          if(first_derivative.y>EnergyOverlapCriteria) first_derivative.y=EnergyOverlapCriteria;
          if(first_derivative.y<-EnergyOverlapCriteria) first_derivative.y=-EnergyOverlapCriteria;
          if(first_derivative.z>EnergyOverlapCriteria) first_derivative.z=EnergyOverlapCriteria;
          if(first_derivative.z<-EnergyOverlapCriteria) first_derivative.z=-EnergyOverlapCriteria;
          second_derivative.ax=second_derivative.bx=second_derivative.cx=0.0;
          second_derivative.ay=second_derivative.by=second_derivative.cy=0.0;
          second_derivative.az=second_derivative.bz=second_derivative.cz=0.0;
          third_derivative=0.0;
        }

        // store energy, and derivatives in "unit cube format"
        CoulombGrid[i][j][k][0]=(float)value;
        CoulombGrid[i][j][k][1]=(float)first_derivative.x*DeltaCoulombGrid.x;
        CoulombGrid[i][j][k][2]=(float)first_derivative.y*DeltaCoulombGrid.y;
        CoulombGrid[i][j][k][3]=(float)first_derivative.z*DeltaCoulombGrid.z;
        CoulombGrid[i][j][k][4]=(float)second_derivative.ay*(DeltaCoulombGrid.x*DeltaCoulombGrid.y);
        CoulombGrid[i][j][k][5]=(float)second_derivative.az*(DeltaCoulombGrid.x*DeltaCoulombGrid.z);
        CoulombGrid[i][j][k][6]=(float)second_derivative.bz*(DeltaCoulombGrid.y*DeltaCoulombGrid.z);
        CoulombGrid[i][j][k][7]=(float)third_derivative*(DeltaCoulombGrid.x*DeltaCoulombGrid.y*DeltaCoulombGrid.z);
      }
    }

    if((int)(teller*percent)>(int)((teller-1.0)*percent))
      fprintf(OutputFilePtr[CurrentSystem],"Percentage finished                      : %d\n",(int)(teller*percent));
    fflush(OutputFilePtr[CurrentSystem]);
  }
  fprintf(stderr, "Writing Grid\n");
  WriteCoulombGrid();
}

int WriteVDWGrid(int l)
{
  int i,j,k,m;
  int ngrid;
  FILE *FilePtr;
  char buffer[256];

  if (STREAM)
  {
    fprintf(stderr, "Streaming not yet supported for this function.");
    exit(0);
  }

  ngrid=NumberOfVDWGridPoints.x*NumberOfVDWGridPoints.y*NumberOfVDWGridPoints.z;

  sprintf(buffer,"%s/share/raspa/grids",RASPA_DIRECTORY);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s",RASPA_DIRECTORY,ForceField);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s/%s",RASPA_DIRECTORY,ForceField,Framework[CurrentSystem].Name[0]);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s/%s/%lf",RASPA_DIRECTORY,ForceField,
    Framework[CurrentSystem].Name[0],(double)SpacingVDWGrid);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s/%s/%lf/%s_%s_%s.grid",
      RASPA_DIRECTORY,
      ForceField,
      Framework[CurrentSystem].Name[0],
      (double)SpacingVDWGrid,
      Framework[CurrentSystem].Name[0],
      PseudoAtoms[l].Name,
      ShiftPotentials?"shifted":"truncated");
  FilePtr=fopen(buffer,"w");

  fwrite(&SpacingVDWGrid,1,sizeof(REAL),FilePtr);
  fwrite(&NumberOfVDWGridPoints,1,sizeof(INT_VECTOR3),FilePtr);
  fwrite(&SizeGrid,1,sizeof(VECTOR),FilePtr);
  fwrite(&ShiftGrid,1,sizeof(VECTOR),FilePtr);
  fwrite(&DeltaVDWGrid,1,sizeof(VECTOR),FilePtr);
  fwrite(&UnitCellSize[CurrentSystem],1,sizeof(VECTOR),FilePtr);
  fwrite(&NumberOfUnitCells[CurrentSystem],1,sizeof(INT_VECTOR3),FilePtr);

  for(m=0;m<8;m++)
    for(i=0;i<=NumberOfVDWGridPoints.x;i++)
      for(j=0;j<=NumberOfVDWGridPoints.y;j++)
        for(k=0;k<=NumberOfVDWGridPoints.z;k++)
          fwrite(&VDWGrid[l][i][j][k][m],1,sizeof(float),FilePtr);

  fclose(FilePtr);
  return 0;
}

void ReadVDWGrid(void)
{
  int i,j,k,l,m;
  VECTOR unit_cell_size;
  INT_VECTOR3 number_of_unit_cells;
  FILE *FilePtr;
  char buffer[256];

  fprintf(stderr, "Reading VDW grid\n");

  for(i=0;i<NumberOfPseudoAtoms;i++)
    VDWGrid[i]=NULL;

  for(l=0;l<NumberOfGrids;l++)
  {
    sprintf(buffer,"%s/share/raspa/grids",RASPA_DIRECTORY);
    sprintf(buffer,"%s/share/raspa/grids/%s/%s/%lf/%s_%s_%s.grid",
        RASPA_DIRECTORY,
        ForceField,
        Framework[CurrentSystem].Name[0],
        (double)SpacingVDWGrid,
        Framework[CurrentSystem].Name[0],
        PseudoAtoms[GridTypeList[l]].Name,
        ShiftPotentials?"shifted":"truncated");
    fprintf(stderr, "Opening: %s\n",buffer);
    if(!(FilePtr=fopen(buffer,"r")))
    {
      fprintf(stderr, "Error:  file %s does not exist.\n",buffer);
      exit(1);
    }

    fread(&SpacingVDWGrid,1,sizeof(REAL),FilePtr);
    fread(&NumberOfVDWGridPoints,1,sizeof(INT_VECTOR3),FilePtr);
    fread(&SizeGrid,1,sizeof(VECTOR),FilePtr);
    fread(&ShiftGrid,1,sizeof(VECTOR),FilePtr);
    fread(&DeltaVDWGrid,1,sizeof(VECTOR),FilePtr);
    fread(&unit_cell_size,1,sizeof(VECTOR),FilePtr);
    fread(&number_of_unit_cells,1,sizeof(INT_VECTOR3),FilePtr);

    if((fabs(UnitCellSize[CurrentSystem].x-unit_cell_size.x)>1e-8)||(fabs(UnitCellSize[CurrentSystem].y-unit_cell_size.y)>1e-8)||
       (fabs(UnitCellSize[CurrentSystem].z-unit_cell_size.z)>1e-8))
    {
      fprintf(stderr, "Error in reading the grid: unit-cell size does not match\n");
      exit(0);
    }

    // Allocate the memory for this grid
    VDWGrid[GridTypeList[l]]=(float****)calloc(NumberOfVDWGridPoints.x+1,sizeof(float***));
    for(i=0;i<=NumberOfVDWGridPoints.x;i++)
    {
      VDWGrid[GridTypeList[l]][i]=(float***)calloc(NumberOfVDWGridPoints.y+1,sizeof(float**));
      for(j=0;j<=NumberOfVDWGridPoints.y;j++)
      {
        VDWGrid[GridTypeList[l]][i][j]=(float**)calloc(NumberOfVDWGridPoints.z+1,sizeof(float*));
        for(k=0;k<=NumberOfVDWGridPoints.z;k++)
          VDWGrid[GridTypeList[l]][i][j][k]=(float*)calloc(8,sizeof(float));
      }
    }

    for(m=0;m<8;m++)
      for(i=0;i<=NumberOfVDWGridPoints.x;i++)
        for(j=0;j<=NumberOfVDWGridPoints.y;j++)
          for(k=0;k<=NumberOfVDWGridPoints.z;k++)
            fread(&VDWGrid[GridTypeList[l]][i][j][k][m],1,sizeof(float),FilePtr);


    fclose(FilePtr);
  }
}

int WriteCoulombGrid(void)
{
  int i,j,k,m,max_size;
  FILE *FilePtr;
  char buffer[256],name[256];

  switch(ChargeMethod)
  {
    case EWALD:
      strcpy(name,"Ewald");
      break;
    case WOLFS_METHOD:
      strcpy(name,"WolfsMethod");
      break;
  }

  max_size=NumberOfCoulombGridPoints.x*NumberOfCoulombGridPoints.y*NumberOfCoulombGridPoints.z;

  sprintf(buffer,"%s/share/raspa/grids",RASPA_DIRECTORY);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s",RASPA_DIRECTORY,ForceField);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s/%s",RASPA_DIRECTORY,ForceField,Framework[CurrentSystem].Name[0]);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s/%s/%lf",RASPA_DIRECTORY,ForceField,
    Framework[CurrentSystem].Name[0],(double)SpacingCoulombGrid);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s/%s/%lf/%dx%dx%d",RASPA_DIRECTORY,ForceField,
    Framework[CurrentSystem].Name[0],(double)SpacingCoulombGrid,
    NumberOfUnitCells[CurrentSystem].x,NumberOfUnitCells[CurrentSystem].y,NumberOfUnitCells[CurrentSystem].z);
  mkdir(buffer,S_IRWXU);
  sprintf(buffer,"%s/share/raspa/grids/%s/%s/%lf/%dx%dx%d/%s_%s_%s.grid",
      RASPA_DIRECTORY,
      ForceField,
      Framework[CurrentSystem].Name[0],
      (double)SpacingCoulombGrid,
      NumberOfUnitCells[CurrentSystem].x,NumberOfUnitCells[CurrentSystem].y,NumberOfUnitCells[CurrentSystem].z,
      Framework[CurrentSystem].Name[0],
      "Electrostatics",
      name);
  FilePtr=fopen(buffer,"w");

  fwrite(&SpacingCoulombGrid,1,sizeof(REAL),FilePtr);
  fwrite(&NumberOfCoulombGridPoints,1,sizeof(INT_VECTOR3),FilePtr);
  fwrite(&SizeGrid,1,sizeof(VECTOR),FilePtr);
  fwrite(&ShiftGrid,1,sizeof(VECTOR),FilePtr);
  fwrite(&DeltaCoulombGrid,1,sizeof(VECTOR),FilePtr);
  fwrite(&UnitCellSize[CurrentSystem],1,sizeof(VECTOR),FilePtr);
  fwrite(&NumberOfUnitCells[CurrentSystem],1,sizeof(INT_VECTOR3),FilePtr);
  fwrite(&EwaldPrecision,1,sizeof(REAL),FilePtr);

  for(m=0;m<8;m++)
    for(i=0;i<=NumberOfCoulombGridPoints.x;i++)
      for(j=0;j<=NumberOfCoulombGridPoints.y;j++)
        for(k=0;k<=NumberOfCoulombGridPoints.z;k++)
          fwrite(&CoulombGrid[i][j][k][m],1,sizeof(float),FilePtr);

  fclose(FilePtr);
  return 0;
}


void ReadCoulombGrid(void)
{
  int i,j,k,m;
  INT_VECTOR3 number_of_unit_cells;
  VECTOR unit_cell_size;
  REAL ewald_precision;
  FILE *FilePtr;
  char buffer[256],name[256];

  if (STREAM)
  {
    fprintf(stderr, "Streaming not yet supported for this function.");
    exit(0);
  }

  switch(ChargeMethod)
  {
    case EWALD:
      strcpy(name,"Ewald");
      break;
    case WOLFS_METHOD:
      strcpy(name,"WolfsMethod");
      break;
  }

  sprintf(buffer,"%s/share/raspa/grids/%s",RASPA_DIRECTORY,ForceField);
  sprintf(buffer,"%s/share/raspa/grids/%s/%s/%lf/%dx%dx%d/%s_%s_%s.grid",
      RASPA_DIRECTORY,
      ForceField,
      Framework[CurrentSystem].Name[0],
      (double)SpacingCoulombGrid,
      NumberOfUnitCells[CurrentSystem].x,NumberOfUnitCells[CurrentSystem].y,NumberOfUnitCells[CurrentSystem].z,
      Framework[CurrentSystem].Name[0],
      "Electrostatics",
      name);
  fprintf(stderr, "Opening: %s\n",buffer);
  if(!(FilePtr=fopen(buffer,"r")))
  {
    fprintf(stderr, "Error:  file %s does not exist.\n",buffer);
    exit(0);
  }
  else
  {
    fread(&SpacingCoulombGrid,1,sizeof(REAL),FilePtr);
    fread(&NumberOfCoulombGridPoints,1,sizeof(INT_VECTOR3),FilePtr);
    fread(&SizeGrid,1,sizeof(VECTOR),FilePtr);
    fread(&ShiftGrid,1,sizeof(VECTOR),FilePtr);
    fread(&DeltaCoulombGrid,1,sizeof(VECTOR),FilePtr);
    fread(&unit_cell_size,1,sizeof(VECTOR),FilePtr);
    fread(&number_of_unit_cells,1,sizeof(INT_VECTOR3),FilePtr);
    fread(&ewald_precision,1,sizeof(REAL),FilePtr);

    if((fabs(UnitCellSize[CurrentSystem].x-unit_cell_size.x)>1e-8)||(fabs(UnitCellSize[CurrentSystem].y-unit_cell_size.y)>1e-8)||
       (fabs(UnitCellSize[CurrentSystem].z-unit_cell_size.z)>1e-8))
    {
      fprintf(stderr, "Error in reading the grid: unit-cell size does not match\n");
      exit(0);
    }

    if((number_of_unit_cells.x!=NumberOfUnitCells[CurrentSystem].x)||
       (number_of_unit_cells.y!=NumberOfUnitCells[CurrentSystem].y)||
       (number_of_unit_cells.z!=NumberOfUnitCells[CurrentSystem].z))
    {
      fprintf(stderr, "Mismatch of number of unitcells, defined: %d,%d,%d, grid: %d,%d,%d\n",
          NumberOfUnitCells[CurrentSystem].x,NumberOfUnitCells[CurrentSystem].y,NumberOfUnitCells[CurrentSystem].z,
          number_of_unit_cells.x,number_of_unit_cells.y,number_of_unit_cells.z);
      exit(0);
    }

    if(fabs(EwaldPrecision-ewald_precision)>1e-8)
    {
      fprintf(stderr, "Mismatch of Ewald precision, currently: %g but the grid had been made using %g\n",
             EwaldPrecision,ewald_precision);
    }

    // Allocate the memory for this grid
    CoulombGrid=(float****)calloc(NumberOfCoulombGridPoints.x+1,sizeof(float***));
    for(i=0;i<=NumberOfCoulombGridPoints.x;i++)
    {
      CoulombGrid[i]=(float***)calloc(NumberOfCoulombGridPoints.y+1,sizeof(float**));
      for(j=0;j<=NumberOfCoulombGridPoints.y;j++)
      {
        CoulombGrid[i][j]=(float**)calloc(NumberOfCoulombGridPoints.z+1,sizeof(float*));
        for(k=0;k<=NumberOfCoulombGridPoints.z;k++)
          CoulombGrid[i][j][k]=(float*)calloc(8,sizeof(float));
      }
    }

    for(m=0;m<8;m++)
      for(i=0;i<=NumberOfCoulombGridPoints.x;i++)
        for(j=0;j<=NumberOfCoulombGridPoints.y;j++)
          for(k=0;k<=NumberOfCoulombGridPoints.z;k++)
            fread(&CoulombGrid[i][j][k][m],1,sizeof(float),FilePtr);


    fclose(FilePtr);
  }
  fprintf(stderr, "End Reading Coulomb Grid\n");
  fprintf(stderr, "Done !!!\n");
}


REAL InterpolateVDWGrid(int typeA,VECTOR pos)
{
  int i,j,k;
  int x0,y0,z0,x1,y1,z1;
  VECTOR s,r;
  REAL value;
  REAL X[64],a[64];

  if(!VDWGrid[typeA])
  {
    fprintf(stderr, "InterpolateVDWGrid: Pseudoatom %d [%s] not tabulated.\n",typeA,PseudoAtoms[typeA].Name);
    exit(0);
  }

  switch(BoundaryCondition[CurrentSystem])
  {
    case CUBIC:
    case RECTANGULAR:
      // the position has to be moved back to the main unit cell using the rectangular boundary condition
      pos.x-=UnitCellSize[CurrentSystem].x*(REAL)(NINT(pos.x/UnitCellSize[CurrentSystem].x));
      pos.y-=UnitCellSize[CurrentSystem].y*(REAL)(NINT(pos.y/UnitCellSize[CurrentSystem].y));
      pos.z-=UnitCellSize[CurrentSystem].z*(REAL)(NINT(pos.z/UnitCellSize[CurrentSystem].z));
      if(pos.x<0.0) pos.x+=UnitCellSize[CurrentSystem].x;
      if(pos.y<0.0) pos.y+=UnitCellSize[CurrentSystem].y;
      if(pos.z<0.0) pos.z+=UnitCellSize[CurrentSystem].z;
      break;
    case TRICLINIC:
    default:
      // the position first has to be moved back to the main unit cell using the triclinic boundary condition
      s.x=InverseUnitCellBox[CurrentSystem].ax*pos.x+InverseUnitCellBox[CurrentSystem].bx*pos.y+InverseUnitCellBox[CurrentSystem].cx*pos.z;
      s.y=InverseUnitCellBox[CurrentSystem].ay*pos.x+InverseUnitCellBox[CurrentSystem].by*pos.y+InverseUnitCellBox[CurrentSystem].cy*pos.z;
      s.z=InverseUnitCellBox[CurrentSystem].az*pos.x+InverseUnitCellBox[CurrentSystem].bz*pos.y+InverseUnitCellBox[CurrentSystem].cz*pos.z;

      s.x-=(REAL)NINT(s.x);
      s.y-=(REAL)NINT(s.y);
      s.z-=(REAL)NINT(s.z);

      if(s.x<0.0) s.x+=1.0;
      if(s.y<0.0) s.y+=1.0;
      if(s.z<0.0) s.z+=1.0;

      pos.x=UnitCellBox[CurrentSystem].ax*s.x+UnitCellBox[CurrentSystem].bx*s.y+UnitCellBox[CurrentSystem].cx*s.z;
      pos.y=UnitCellBox[CurrentSystem].ay*s.x+UnitCellBox[CurrentSystem].by*s.y+UnitCellBox[CurrentSystem].cy*s.z;
      pos.z=UnitCellBox[CurrentSystem].az*s.x+UnitCellBox[CurrentSystem].bz*s.y+UnitCellBox[CurrentSystem].cz*s.z;
      break;
  }

  s.x=((pos.x-ShiftGrid.x)/SizeGrid.x)*(REAL)(NumberOfVDWGridPoints.x);
  s.y=((pos.y-ShiftGrid.y)/SizeGrid.y)*(REAL)(NumberOfVDWGridPoints.y);
  s.z=((pos.z-ShiftGrid.z)/SizeGrid.z)*(REAL)(NumberOfVDWGridPoints.z);

  // find the corresponding cell, between 0 and NumberOfVDWGridPoints
  // determine lower boundary
  x0=(int)s.x;
  y0=(int)s.y;
  z0=(int)s.z;

  // determine upper boundary, apply periodic boundary condition
  x1=x0+1;
  y1=y0+1;
  z1=z0+1;

  // find the corresponding position within that cell (between 0.0 and 1.0)
  r.x=(s.x-x0);
  r.y=(s.y-y0);
  r.z=(s.z-z0);

  // retrieve the grid value and the derivatives
  for(i=0;i<8;i++)
  {
    X[0+i*8]=VDWGrid[typeA][x0][y0][z0][i];
    X[1+i*8]=VDWGrid[typeA][x1][y0][z0][i];
    X[2+i*8]=VDWGrid[typeA][x0][y1][z0][i];
    X[3+i*8]=VDWGrid[typeA][x1][y1][z0][i];
    X[4+i*8]=VDWGrid[typeA][x0][y0][z1][i];
    X[5+i*8]=VDWGrid[typeA][x1][y0][z1][i];
    X[6+i*8]=VDWGrid[typeA][x0][y1][z1][i];
    X[7+i*8]=VDWGrid[typeA][x1][y1][z1][i];
  }

  // cap values to avoid a negative interpolation result
  for(i=0;i<8;i++)
    if(X[i]>1e10) return 1e8;

  for (i=0;i<64;i++)
  {
    a[i]=(double)(0.0);
    for (j=0;j<64;j++)
      a[i]+=Coeff[i][j]*X[j];
  }

  // energy
  value=0.0;
  for (i=0;i<4;i++)
    for (j=0;j<4;j++)
      for (k=0;k<4;k++)
        value+=a[i+4*j+16*k]*pow(r.x,i)*pow(r.y,j)*pow(r.z,k);

  return value;
}

REAL InterpolateVDWForceGrid(int typeA,VECTOR pos,VECTOR *Force)
{
  int i,j,k;
  int x0,y0,z0,x1,y1,z1;
  VECTOR s,r;
  REAL value;
  REAL X[64],a[64];

  if(!VDWGrid[typeA])
  {
    fprintf(stderr, "InterpolateVDWGrid: Pseudoatom %d [%s] not tabulated.\n",typeA,PseudoAtoms[typeA].Name);
    exit(0);
  }

  switch(BoundaryCondition[CurrentSystem])
  {
    case CUBIC:
    case RECTANGULAR:
      // the position has to be moved back to the main unit cell using the rectangular boundary condition
      pos.x-=UnitCellSize[CurrentSystem].x*(REAL)(NINT(pos.x/UnitCellSize[CurrentSystem].x));
      pos.y-=UnitCellSize[CurrentSystem].y*(REAL)(NINT(pos.y/UnitCellSize[CurrentSystem].y));
      pos.z-=UnitCellSize[CurrentSystem].z*(REAL)(NINT(pos.z/UnitCellSize[CurrentSystem].z));
      if(pos.x<0.0) pos.x+=UnitCellSize[CurrentSystem].x;
      if(pos.y<0.0) pos.y+=UnitCellSize[CurrentSystem].y;
      if(pos.z<0.0) pos.z+=UnitCellSize[CurrentSystem].z;
      break;
    case TRICLINIC:
    default:
      // the position first has to be moved back to the main unit cell using the triclinic boundary condition
      s.x=InverseUnitCellBox[CurrentSystem].ax*pos.x+InverseUnitCellBox[CurrentSystem].bx*pos.y+InverseUnitCellBox[CurrentSystem].cx*pos.z;
      s.y=InverseUnitCellBox[CurrentSystem].ay*pos.x+InverseUnitCellBox[CurrentSystem].by*pos.y+InverseUnitCellBox[CurrentSystem].cy*pos.z;
      s.z=InverseUnitCellBox[CurrentSystem].az*pos.x+InverseUnitCellBox[CurrentSystem].bz*pos.y+InverseUnitCellBox[CurrentSystem].cz*pos.z;

      s.x-=(REAL)NINT(s.x);
      s.y-=(REAL)NINT(s.y);
      s.z-=(REAL)NINT(s.z);

      if(s.x<0.0) s.x+=1.0;
      if(s.y<0.0) s.y+=1.0;
      if(s.z<0.0) s.z+=1.0;

      pos.x=UnitCellBox[CurrentSystem].ax*s.x+UnitCellBox[CurrentSystem].bx*s.y+UnitCellBox[CurrentSystem].cx*s.z;
      pos.y=UnitCellBox[CurrentSystem].ay*s.x+UnitCellBox[CurrentSystem].by*s.y+UnitCellBox[CurrentSystem].cy*s.z;
      pos.z=UnitCellBox[CurrentSystem].az*s.x+UnitCellBox[CurrentSystem].bz*s.y+UnitCellBox[CurrentSystem].cz*s.z;
      break;
  }

  s.x=((pos.x-ShiftGrid.x)/SizeGrid.x)*(REAL)NumberOfVDWGridPoints.x;
  s.y=((pos.y-ShiftGrid.y)/SizeGrid.y)*(REAL)NumberOfVDWGridPoints.y;
  s.z=((pos.z-ShiftGrid.z)/SizeGrid.z)*(REAL)NumberOfVDWGridPoints.z;

  // find the corresponding cell, between 0 and NumberOfVDWGridPoints
  // determine lower boundary
  x0=(int)s.x;
  y0=(int)s.y;
  z0=(int)s.z;

  // determine upper boundary, apply periodic boundary condition
  x1=x0+1;
  y1=y0+1;
  z1=z0+1;

  // find the corresponding position within that cell (between 0.0 and 1.0)
  r.x=(s.x-x0);
  r.y=(s.y-y0);
  r.z=(s.z-z0);

  // retrieve the grid value and the derivatives
  for(i=0;i<8;i++)
  {
    X[0+i*8]=VDWGrid[typeA][x0][y0][z0][i];
    X[1+i*8]=VDWGrid[typeA][x1][y0][z0][i];
    X[2+i*8]=VDWGrid[typeA][x0][y1][z0][i];
    X[3+i*8]=VDWGrid[typeA][x1][y1][z0][i];
    X[4+i*8]=VDWGrid[typeA][x0][y0][z1][i];
    X[5+i*8]=VDWGrid[typeA][x1][y0][z1][i];
    X[6+i*8]=VDWGrid[typeA][x0][y1][z1][i];
    X[7+i*8]=VDWGrid[typeA][x1][y1][z1][i];
  }

  // cap values to avoid a negative interpolation result
  for(i=0;i<8;i++)
    if(X[i]>1e10) return 1e8;

  for (i=0;i<64;i++)
  {
    a[i]=(double)(0.0);
    for (j=0;j<64;j++)
      a[i]+=Coeff[i][j]*X[j];
  }

  value=0.0;
  for (i=1;i<4;i++)
    for (j=0;j<4;j++)
      for (k=0;k<4;k++)
        value+=i*a[i+4*j+16*k]*pow(r.x,i-1)*pow(r.y,j)*pow(r.z,k);
  Force->x=-value/DeltaVDWGrid.x;

  value=0.0;
  for (i=0;i<4;i++)
    for (j=1;j<4;j++)
      for (k=0;k<4;k++)
        value+=j*a[i+4*j+16*k]*pow(r.x,i)*pow(r.y,j-1)*pow(r.z,k);
  Force->y=-value/DeltaVDWGrid.y;

  value=0.0;
  for (i=0;i<4;i++)
    for (j=0;j<4;j++)
      for (k=1;k<4;k++)
        value+=k*a[i+4*j+16*k]*pow(r.x,i)*pow(r.y,j)*pow(r.z,k-1);
  Force->z=-value/DeltaVDWGrid.z;

  // energy
  value=0.0;
  for (i=0;i<4;i++)
    for (j=0;j<4;j++)
      for (k=0;k<4;k++)
        value+=a[i+4*j+16*k]*pow(r.x,i)*pow(r.y,j)*pow(r.z,k);

  return value;
}

REAL InterpolateCoulombGrid(int typeA,VECTOR pos)
{
  int i,j,k;
  int x0,y0,z0,x1,y1,z1;
  VECTOR s,r;
  REAL value;
  REAL X[64],a[64];

  if(!CoulombGrid)
  {
    fprintf(stderr, "InterpolateCoulombGrid: Pseudoatom %d [%s] not tabulated.\n",typeA,PseudoAtoms[typeA].Name);
    exit(0);
  }

  switch(BoundaryCondition[CurrentSystem])
  {
    case CUBIC:
    case RECTANGULAR:
      // the position has to be moved back to the main unit cell using the rectangular boundary condition
      pos.x-=UnitCellSize[CurrentSystem].x*(REAL)(NINT(pos.x/UnitCellSize[CurrentSystem].x));
      pos.y-=UnitCellSize[CurrentSystem].y*(REAL)(NINT(pos.y/UnitCellSize[CurrentSystem].y));
      pos.z-=UnitCellSize[CurrentSystem].z*(REAL)(NINT(pos.z/UnitCellSize[CurrentSystem].z));
      if(pos.x<0.0) pos.x+=UnitCellSize[CurrentSystem].x;
      if(pos.y<0.0) pos.y+=UnitCellSize[CurrentSystem].y;
      if(pos.z<0.0) pos.z+=UnitCellSize[CurrentSystem].z;
      break;
    case TRICLINIC:
    default:
      // the position first has to be moved back to the main unit cell using the triclinic boundary condition
      s.x=InverseUnitCellBox[CurrentSystem].ax*pos.x+InverseUnitCellBox[CurrentSystem].bx*pos.y+InverseUnitCellBox[CurrentSystem].cx*pos.z;
      s.y=InverseUnitCellBox[CurrentSystem].ay*pos.x+InverseUnitCellBox[CurrentSystem].by*pos.y+InverseUnitCellBox[CurrentSystem].cy*pos.z;
      s.z=InverseUnitCellBox[CurrentSystem].az*pos.x+InverseUnitCellBox[CurrentSystem].bz*pos.y+InverseUnitCellBox[CurrentSystem].cz*pos.z;

      s.x-=(REAL)NINT(s.x);
      s.y-=(REAL)NINT(s.y);
      s.z-=(REAL)NINT(s.z);

      if(s.x<0.0) s.x+=1.0;
      if(s.y<0.0) s.y+=1.0;
      if(s.z<0.0) s.z+=1.0;

      pos.x=UnitCellBox[CurrentSystem].ax*s.x+UnitCellBox[CurrentSystem].bx*s.y+UnitCellBox[CurrentSystem].cx*s.z;
      pos.y=UnitCellBox[CurrentSystem].ay*s.x+UnitCellBox[CurrentSystem].by*s.y+UnitCellBox[CurrentSystem].cy*s.z;
      pos.z=UnitCellBox[CurrentSystem].az*s.x+UnitCellBox[CurrentSystem].bz*s.y+UnitCellBox[CurrentSystem].cz*s.z;
      break;
  }

  s.x=((pos.x-ShiftGrid.x)/SizeGrid.x)*(REAL)NumberOfCoulombGridPoints.x;
  s.y=((pos.y-ShiftGrid.y)/SizeGrid.y)*(REAL)NumberOfCoulombGridPoints.y;
  s.z=((pos.z-ShiftGrid.z)/SizeGrid.z)*(REAL)NumberOfCoulombGridPoints.z;


  // find the corresponding cell, between 0 and NumberOfCoulombGridPoints
  // determine lower boundary
  x0=(int)s.x;
  y0=(int)s.y;
  z0=(int)s.z;

  // determine upper boundary, apply periodic boundary condition
  x1=x0+1;
  y1=y0+1;
  z1=z0+1;

  // find the corresponding position within that cell (between 0.0 and 1.0)
  r.x=(s.x-x0);
  r.y=(s.y-y0);
  r.z=(s.z-z0);

  // retrieve the grid value and the derivatives
  for(i=0;i<8;i++)
  {
    X[0+i*8]=CoulombGrid[x0][y0][z0][i];
    X[1+i*8]=CoulombGrid[x1][y0][z0][i];
    X[2+i*8]=CoulombGrid[x0][y1][z0][i];
    X[3+i*8]=CoulombGrid[x1][y1][z0][i];
    X[4+i*8]=CoulombGrid[x0][y0][z1][i];
    X[5+i*8]=CoulombGrid[x1][y0][z1][i];
    X[6+i*8]=CoulombGrid[x0][y1][z1][i];
    X[7+i*8]=CoulombGrid[x1][y1][z1][i];
  }

  for (i=0;i<64;i++)
  {
    a[i]=(double)(0.0);
    for (j=0;j<64;j++)
      a[i]+=Coeff[i][j]*X[j];
  }

  // energy
  value=0.0;
  for (i=0;i<4;i++)
    for (j=0;j<4;j++)
      for (k=0;k<4;k++)
        value+=a[i+4*j+16*k]*pow(r.x,i)*pow(r.y,j)*pow(r.z,k);

  return PseudoAtoms[typeA].Charge1*value;
}

REAL InterpolateCoulombForceGrid(int typeA,VECTOR pos,VECTOR *Force)
{
  int i,j,k;
  int x0,y0,z0,x1,y1,z1;
  VECTOR s,r;
  REAL value;
  REAL X[64],a[64];

  if(!CoulombGrid)
  {
    fprintf(stderr, "InterpolateCoulombGrid: Pseudoatom %d [%s] not tabulated.\n",typeA,PseudoAtoms[typeA].Name);
    exit(0);
  }

  switch(BoundaryCondition[CurrentSystem])
  {
    case CUBIC:
    case RECTANGULAR:
      // the position has to be moved back to the main unit cell using the rectangular boundary condition
      pos.x-=UnitCellSize[CurrentSystem].x*(REAL)(NINT(pos.x/UnitCellSize[CurrentSystem].x));
      pos.y-=UnitCellSize[CurrentSystem].y*(REAL)(NINT(pos.y/UnitCellSize[CurrentSystem].y));
      pos.z-=UnitCellSize[CurrentSystem].z*(REAL)(NINT(pos.z/UnitCellSize[CurrentSystem].z));
      if(pos.x<0.0) pos.x+=UnitCellSize[CurrentSystem].x;
      if(pos.y<0.0) pos.y+=UnitCellSize[CurrentSystem].y;
      if(pos.z<0.0) pos.z+=UnitCellSize[CurrentSystem].z;
      break;
    case TRICLINIC:
    default:
      // the position first has to be moved back to the main unit cell using the triclinic boundary condition
      s.x=InverseUnitCellBox[CurrentSystem].ax*pos.x+InverseUnitCellBox[CurrentSystem].bx*pos.y+InverseUnitCellBox[CurrentSystem].cx*pos.z;
      s.y=InverseUnitCellBox[CurrentSystem].ay*pos.x+InverseUnitCellBox[CurrentSystem].by*pos.y+InverseUnitCellBox[CurrentSystem].cy*pos.z;
      s.z=InverseUnitCellBox[CurrentSystem].az*pos.x+InverseUnitCellBox[CurrentSystem].bz*pos.y+InverseUnitCellBox[CurrentSystem].cz*pos.z;

      s.x-=(REAL)NINT(s.x);
      s.y-=(REAL)NINT(s.y);
      s.z-=(REAL)NINT(s.z);

      if(s.x<0.0) s.x+=1.0;
      if(s.y<0.0) s.y+=1.0;
      if(s.z<0.0) s.z+=1.0;

      pos.x=UnitCellBox[CurrentSystem].ax*s.x+UnitCellBox[CurrentSystem].bx*s.y+UnitCellBox[CurrentSystem].cx*s.z;
      pos.y=UnitCellBox[CurrentSystem].ay*s.x+UnitCellBox[CurrentSystem].by*s.y+UnitCellBox[CurrentSystem].cy*s.z;
      pos.z=UnitCellBox[CurrentSystem].az*s.x+UnitCellBox[CurrentSystem].bz*s.y+UnitCellBox[CurrentSystem].cz*s.z;
      break;
  }

  s.x=((pos.x-ShiftGrid.x)/SizeGrid.x)*(REAL)NumberOfCoulombGridPoints.x;
  s.y=((pos.y-ShiftGrid.y)/SizeGrid.y)*(REAL)NumberOfCoulombGridPoints.y;
  s.z=((pos.z-ShiftGrid.z)/SizeGrid.z)*(REAL)NumberOfCoulombGridPoints.z;

  // find the corresponding cell, between 0 and NumberOfCoulombGridPoints
  // determine lower boundary
  x0=(int)s.x;
  y0=(int)s.y;
  z0=(int)s.z;

  // determine upper boundary, apply periodic boundary condition
  x1=x0+1;
  y1=y0+1;
  z1=z0+1;

  // find the corresponding position within that cell (between 0.0 and 1.0)
  r.x=(s.x-x0);
  r.y=(s.y-y0);
  r.z=(s.z-z0);

  // retrieve the grid value and the derivatives
  for(i=0;i<8;i++)
  {
    X[0+i*8]=CoulombGrid[x0][y0][z0][i];
    X[1+i*8]=CoulombGrid[x1][y0][z0][i];
    X[2+i*8]=CoulombGrid[x0][y1][z0][i];
    X[3+i*8]=CoulombGrid[x1][y1][z0][i];
    X[4+i*8]=CoulombGrid[x0][y0][z1][i];
    X[5+i*8]=CoulombGrid[x1][y0][z1][i];
    X[6+i*8]=CoulombGrid[x0][y1][z1][i];
    X[7+i*8]=CoulombGrid[x1][y1][z1][i];
  }

  for (i=0;i<64;i++)
  {
    a[i]=(double)(0.0);
    for (j=0;j<64;j++)
      a[i]+=Coeff[i][j]*X[j];
  }

  value=0.0;
  for (i=1;i<4;i++)
    for (j=0;j<4;j++)
      for (k=0;k<4;k++)
        value+=i*a[i+4*j+16*k]*pow(r.x,i-1)*pow(r.y,j)*pow(r.z,k);
  Force->x=-PseudoAtoms[typeA].Charge1*value/DeltaCoulombGrid.x;

  value=0.0;
  for (i=0;i<4;i++)
    for (j=1;j<4;j++)
      for (k=0;k<4;k++)
        value+=j*a[i+4*j+16*k]*pow(r.x,i)*pow(r.y,j-1)*pow(r.z,k);
  Force->y=-PseudoAtoms[typeA].Charge1*value/DeltaCoulombGrid.y;

  value=0.0;
  for (i=0;i<4;i++)
    for (j=0;j<4;j++)
      for (k=1;k<4;k++)
        value+=k*a[i+4*j+16*k]*pow(r.x,i)*pow(r.y,j)*pow(r.z,k-1);
  Force->z=-PseudoAtoms[typeA].Charge1*value/DeltaCoulombGrid.z;

  // energy
  value=0.0;
  for (i=0;i<4;i++)
    for (j=0;j<4;j++)
      for (k=0;k<4;k++)
        value+=a[i+4*j+16*k]*pow(r.x,i)*pow(r.y,j)*pow(r.z,k);

  return PseudoAtoms[typeA].Charge1*value;
}

int HasVDWInteractionWithFramework(int type)
{
  int i;

  for(i=1;i<NumberOfPseudoAtoms;i++)
  {
    if(PseudoAtoms[i].FrameworkAtom)
      if((PotentialType[type][i]!=ZERO_POTENTIAL)&&(PotentialType[type][i]!=NONE)) return TRUE;
  }
  return FALSE;
}


void TestForceGrid(FILE *FilePtr)
{
  int i,j,k,typeA;
  REAL resf[8],rest[8],ebolt[8],bolt[8],bolf[8],ebolf[8],errb[8],eeb[8];
  REAL Vlj,Vcoul;
  VECTOR Force,CoulombForce;
  POINT pos,s;
  int StoreBiasingMethod,already_present;

  StoreBiasingMethod=BiasingMethod;
  BiasingMethod=LJ_AND_REAL_BIASING;

  // compute the modified VDW sites for anisotropic models
  CalculateAnisotropicSites();

  fprintf(FilePtr,"\n");
  fprintf(FilePtr,"Number Of Gridpoints for VDW-interactions: %d\n",
    NumberOfVDWGridPoints.x*NumberOfVDWGridPoints.y*NumberOfVDWGridPoints.z);
  fprintf(FilePtr,"=============================================================\n");
  fprintf(FilePtr,"NumberOfGridPoints [x]: %d\n",NumberOfVDWGridPoints.x);
  fprintf(FilePtr,"NumberOfGridPoints [y]: %d\n",NumberOfVDWGridPoints.y);
  fprintf(FilePtr,"NumberOfGridPoints [z]: %d\n",NumberOfVDWGridPoints.z);
  fprintf(FilePtr,"\n");

  fprintf(FilePtr,"Number Of Gridpoints for Coulomb-interactions: %d\n",
    NumberOfCoulombGridPoints.x*NumberOfCoulombGridPoints.y*NumberOfCoulombGridPoints.z);
  fprintf(FilePtr,"=============================================================\n");
  fprintf(FilePtr,"NumberOfGridPoints [x]: %d\n",NumberOfCoulombGridPoints.x);
  fprintf(FilePtr,"NumberOfGridPoints [y]: %d\n",NumberOfCoulombGridPoints.y);
  fprintf(FilePtr,"NumberOfGridPoints [z]: %d\n",NumberOfCoulombGridPoints.z);
  fprintf(FilePtr,"\n");

  for(typeA=0;typeA<NumberOfPseudoAtoms;typeA++)
  {
    if(VDWGrid[typeA])
    {
      for(j=0;j<8;j++)
      {
        bolt[j]=0.0;
        ebolt[j]=0.0;
        bolf[j]=0.0;
        ebolf[j]=0.0;
        errb[j]=0.0;
        eeb[j]=0.0;
      }

      for(i=0;i<5000;i++)
      {
        switch(BoundaryCondition[CurrentSystem])
        {
          case CUBIC:
          case RECTANGULAR:
            pos.x=Box[CurrentSystem].ax*RandomNumber();
            pos.y=Box[CurrentSystem].by*RandomNumber();
            pos.z=Box[CurrentSystem].cz*RandomNumber();
            break;
          case TRICLINIC:
            s.x=RandomNumber();
            s.y=RandomNumber();
            s.z=RandomNumber();
            pos.x=Box[CurrentSystem].ax*s.x+Box[CurrentSystem].bx*s.y+Box[CurrentSystem].cx*s.z;
            pos.y=Box[CurrentSystem].ay*s.x+Box[CurrentSystem].by*s.y+Box[CurrentSystem].cy*s.z;
            pos.z=Box[CurrentSystem].az*s.x+Box[CurrentSystem].bz*s.y+Box[CurrentSystem].cz*s.z;
            break;
        }

        Framework[CurrentSystem].FrameworkModel=FULL;
        CalculateFrameworkForceAtPosition(pos,typeA,&Vlj,&Force,&Vcoul,&CoulombForce);

        // problem: to which component belongs this type?
        //if(BlockedPocketGridTest(pos))
        //  Vlj=Force.x=Force.y=Force.z=EnergyOverlapCriteria;

        resf[0]=Vlj;
        resf[1]=Force.x;
        resf[2]=Force.y;
        resf[3]=Force.z;

        resf[4]=Vcoul;
        resf[5]=CoulombForce.x;
        resf[6]=CoulombForce.y;
        resf[7]=CoulombForce.z;

        for(j=0;j<4;j++)
        {
          bolf[j]+=exp(-resf[0]*Beta[CurrentSystem]);
          ebolf[j]+=resf[j]*exp(-resf[0]*Beta[CurrentSystem]);
        }

        if(!HasVDWInteractionWithFramework(typeA))
        {
          CalculateFrameworkForceAtPosition(pos,0,&Vlj,&Force,&Vcoul,&CoulombForce);
          resf[0]=Vlj;
          resf[1]=Force.x;
          resf[2]=Force.y;
          resf[3]=Force.z;
        }

        Framework[CurrentSystem].FrameworkModel=GRID;
        CalculateFrameworkForceAtPosition(pos,typeA,&Vlj,&Force,&Vcoul,&CoulombForce);

        rest[0]=Vlj;
        rest[1]=Force.x;
        rest[2]=Force.y;
        rest[3]=Force.z;

        rest[4]=Vcoul;
        rest[5]=CoulombForce.x;
        rest[6]=CoulombForce.y;
        rest[7]=CoulombForce.z;

        for(j=0;j<4;j++)
        {
          bolt[j]+=exp(-rest[0]*Beta[CurrentSystem]);
          ebolt[j]+=rest[j]*exp(-rest[0]*Beta[CurrentSystem]);

          errb[j]+=exp(-resf[0]*Beta[CurrentSystem])*SQR(resf[j]-rest[j]);
          eeb[j]+=exp(-resf[0]*Beta[CurrentSystem])*SQR(resf[j]);
        }

        // if the atom does not have VDW, then use the 'UNIT'-atom
        if(!HasVDWInteractionWithFramework(typeA))
        {
          CalculateFrameworkForceAtPosition(pos,0,&Vlj,&Force,&Vcoul,&CoulombForce);
          rest[0]=Vlj;
          rest[1]=Force.x;
          rest[2]=Force.y;
          rest[3]=Force.z;
        }

        for(j=4;j<8;j++)
        {
          bolt[j]+=exp(-rest[0]*Beta[CurrentSystem]);
          ebolt[j]+=rest[j]*exp(-rest[0]*Beta[CurrentSystem]);

          bolf[j]+=exp(-resf[0]*Beta[CurrentSystem]);
          ebolf[j]+=resf[j]*exp(-resf[0]*Beta[CurrentSystem]);

          errb[j]+=exp(-resf[0]*Beta[CurrentSystem])*SQR(resf[j]-rest[j]);
          eeb[j]+=exp(-resf[0]*Beta[CurrentSystem])*SQR(resf[j]);
        }
      }

      fprintf(FilePtr,"\n\n");
      fprintf(FilePtr,"PseudoAtom %d Framework-[%s]\n",typeA,PseudoAtoms[typeA].Name);

      fprintf(FilePtr,"=========================================================================================\n");
      fprintf(FilePtr,"\tBoltzmann average energy VDW (table)                 : %18.12lf\n",(double)(ebolt[0]/bolt[0]));
      fprintf(FilePtr,"\tBoltzmann average energy VDW (full)                  : %18.12lf\n",(double)(ebolf[0]/bolf[0]));
      fprintf(FilePtr,"\tBoltzmann relative error VDW                         : %18.12lf\n",(double)(fabs(ebolt[0])<1e-8?0.0:sqrt(errb[0]/eeb[0])));
      if(fabs(ebolt[0])<1e-8?0.0:sqrt(errb[0]/eeb[0])>0.01) fprintf(FilePtr,"\tError: VDW energy interpolation table is wrong...\n");
      if(PseudoAtoms[typeA].HasCharges)
      {
        fprintf(FilePtr,"\tBoltzmann average energy Coulomb (table)             : %18.12lf\n",(double)(ebolt[4]/bolt[4]));
        fprintf(FilePtr,"\tBoltzmann average energy Coulomb (full)              : %18.12lf\n",(double)(ebolf[4]/bolf[4]));
        fprintf(FilePtr,"\tBoltzmann relative error Coulomb                     : %18.12lf\n",(double)(fabs(ebolt[4])<1e-8?0.0:sqrt(errb[4]/eeb[4])));
        if(fabs(ebolt[4])<1e-8?0.0:sqrt(errb[4]/eeb[4])>0.01) fprintf(FilePtr,"\tError: Coulomb energy interpolation table is wrong...\n");
      }

      if((fabs(ebolt[0])<1e-8?0.0:sqrt(errb[0]/eeb[0])>0.01)||
         (PseudoAtoms[typeA].HasCharges&&(fabs(ebolt[4])<1e-8?0.0:sqrt(errb[4]/eeb[4])>0.01)))
      {
        already_present=FALSE;
        for(k=0;k<NumberOfWarnings[CurrentSystem];k++)
          if(Warnings[CurrentSystem][k]==GRID_ERROR_ENERGY) already_present=TRUE;
        if((!ContinueAfterCrash)&&(!already_present))
        {
          if(NumberOfWarnings[k]<MAX_NUMBER_OF_WARNINGS)
          {
            Warnings[CurrentSystem][NumberOfWarnings[CurrentSystem]]=GRID_ERROR_ENERGY;
            NumberOfWarnings[CurrentSystem]++;
          }
        }
      }


      fprintf(FilePtr,"=========================================================================================\n");
      fprintf(FilePtr,"\tBoltzmann average Force[x] VDW (table)               : %18.12lf\n",(double)(ebolt[1]/bolt[1]));
      fprintf(FilePtr,"\tBoltzmann average Force[x] VDW (full)                : %18.12lf\n",(double)(ebolf[1]/bolf[1]));
      fprintf(FilePtr,"\tBoltzmann relative error VDW                         : %18.12lf\n",(double)(fabs(ebolt[1])<1e-8?0.0:sqrt(errb[1]/eeb[1])));
      if(fabs(ebolt[1])<1e-8?0.0:sqrt(errb[1]/eeb[1])>0.01) fprintf(FilePtr,"\tError: VDW Force[x] interpolation table is wrong...\n");
      if(PseudoAtoms[typeA].HasCharges)
      {
        fprintf(FilePtr,"\tBoltzmann average Force[x] Coulomb (table)           : %18.12lf\n",(double)(ebolt[5]/bolt[5]));
        fprintf(FilePtr,"\tBoltzmann average Force[x] Coulomb (full)            : %18.12lf\n",(double)(ebolf[5]/bolf[5]));
        fprintf(FilePtr,"\tBoltzmann relative error Coulomb                     : %18.12lf\n",(double)(fabs(ebolt[5])<1e-8?0.0:sqrt(errb[5]/eeb[5])));
        if(fabs(ebolt[5])<1e-8?0.0:sqrt(errb[5]/eeb[5])>0.01) fprintf(FilePtr,"\tError: Coulomb Force[z] interpolation table is wrong...\n");
      }
      fprintf(FilePtr,"=========================================================================================\n");
      fprintf(FilePtr,"\tBoltzmann average Force[y] VDW (table)               : %18.12lf\n",(double)(ebolt[2]/bolt[2]));
      fprintf(FilePtr,"\tBoltzmann average Force[y] VDW (full)                : %18.12lf\n",(double)(ebolf[2]/bolf[2]));
      fprintf(FilePtr,"\tBoltzmann relative error VDW                         : %18.12lf\n",(double)(fabs(ebolt[2])<1e-8?0.0:sqrt(errb[2]/eeb[2])));
      if(fabs(ebolt[2])<1e-8?0.0:sqrt(errb[2]/eeb[2])>0.01) fprintf(FilePtr,"\tError: VDW Force[y] interpolation table is wrong...\n");
      if(PseudoAtoms[typeA].HasCharges)
      {
        fprintf(FilePtr,"\tBoltzmann average Force[y] Coulomb (table)           : %18.12lf\n",(double)(ebolt[6]/bolt[6]));
        fprintf(FilePtr,"\tBoltzmann average Force[y] Coulomb (full)            : %18.12lf\n",(double)(ebolf[6]/bolf[6]));
        fprintf(FilePtr,"\tBoltzmann relative error Coulomb                     : %18.12lf\n",(double)(fabs(ebolt[6])<1e-8?0.0:sqrt(errb[6]/eeb[6])));
        if(fabs(ebolt[6])<1e-8?0.0:sqrt(errb[6]/eeb[6])>0.01) fprintf(FilePtr,"\tError: Coulomb Force[y] interpolation table is wrong...\n");
      }
      fprintf(FilePtr,"=========================================================================================\n");
      fprintf(FilePtr,"\tBoltzmann average Force[z] VDW (table)               : %18.12lf\n",(double)(ebolt[3]/bolt[3]));
      fprintf(FilePtr,"\tBoltzmann average Force[z] VDW (full)                : %18.12lf\n",(double)(ebolf[3]/bolf[3]));
      fprintf(FilePtr,"\tBoltzmann relative error VDW                         : %18.12lf\n",(double)(fabs(ebolt[3])<1e-8?0.0:sqrt(errb[3]/eeb[3])));
      if(fabs(ebolt[3])<1e-8?0.0:sqrt(errb[3]/eeb[3])>0.01) fprintf(FilePtr,"\tError: VDW Force[z] interpolation table is wrong...\n");
      if(PseudoAtoms[typeA].HasCharges)
      {
        fprintf(FilePtr,"\tBoltzmann average Force[z] Coulomb (table)           : %18.12lf\n",(double)(ebolt[7]/bolt[7]));
        fprintf(FilePtr,"\tBoltzmann average Force[z] Coulomb (full)            : %18.12lf\n",(double)(ebolf[7]/bolf[7]));
        fprintf(FilePtr,"\tBoltzmann relative error Coulomb                     : %18.12lf\n",(double)(fabs(ebolt[7])<1e-8?0.0:sqrt(errb[7]/eeb[7])));
        if(fabs(ebolt[7])<1e-8?0.0:sqrt(errb[7]/eeb[7])>0.01) fprintf(FilePtr,"\tError: VDW Force[z] interpolation table is wrong...\n");
      }

      if((fabs(ebolt[1])<1e-8?0.0:sqrt(errb[1]/eeb[1])>0.01)||
         (fabs(ebolt[2])<1e-8?0.0:sqrt(errb[2]/eeb[2])>0.01)||
         (fabs(ebolt[3])<1e-8?0.0:sqrt(errb[3]/eeb[3])>0.01)||
         (PseudoAtoms[typeA].HasCharges&&(
         (fabs(ebolt[5])<1e-8?0.0:sqrt(errb[5]/eeb[5])>0.01)||
         (fabs(ebolt[6])<1e-8?0.0:sqrt(errb[6]/eeb[6])>0.01)||
         (fabs(ebolt[7])<1e-8?0.0:sqrt(errb[7]/eeb[7])>0.01))))
      {
        already_present=FALSE;
        for(k=0;k<NumberOfWarnings[CurrentSystem];k++)
          if(Warnings[CurrentSystem][k]==GRID_ERROR_FORCE) already_present=TRUE;
        if((!ContinueAfterCrash)&&(!already_present))
        {
          if(NumberOfWarnings[k]<MAX_NUMBER_OF_WARNINGS)
          {
            Warnings[CurrentSystem][NumberOfWarnings[CurrentSystem]]=GRID_ERROR_FORCE;
            NumberOfWarnings[CurrentSystem]++;
          }
        }
      }
    }
  }
  BiasingMethod=StoreBiasingMethod;
  Framework[CurrentSystem].FrameworkModel=GRID;
}

INT_VECTOR3 ConvertXYZPositionToGridIndex(VECTOR pos)
{
  VECTOR s;
  INT_VECTOR3 t;

  switch(BoundaryCondition[CurrentSystem])
  {
    case CUBIC:
    case RECTANGULAR:
      // the position has to be moved back to the main unit cell using the rectangular boundary condition
      pos.x-=UnitCellSize[CurrentSystem].x*(REAL)(NINT(pos.x/UnitCellSize[CurrentSystem].x));
      pos.y-=UnitCellSize[CurrentSystem].y*(REAL)(NINT(pos.y/UnitCellSize[CurrentSystem].y));
      pos.z-=UnitCellSize[CurrentSystem].z*(REAL)(NINT(pos.z/UnitCellSize[CurrentSystem].z));
      if(pos.x<0.0) pos.x+=UnitCellSize[CurrentSystem].x;
      if(pos.y<0.0) pos.y+=UnitCellSize[CurrentSystem].y;
      if(pos.z<0.0) pos.z+=UnitCellSize[CurrentSystem].z;
      break;
    case TRICLINIC:
    default:
      // the position first has to be moved back to the main unit cell using the triclinic boundary condition
      s.x=InverseUnitCellBox[CurrentSystem].ax*pos.x+InverseUnitCellBox[CurrentSystem].bx*pos.y+InverseUnitCellBox[CurrentSystem].cx*pos.z;
      s.y=InverseUnitCellBox[CurrentSystem].ay*pos.x+InverseUnitCellBox[CurrentSystem].by*pos.y+InverseUnitCellBox[CurrentSystem].cy*pos.z;
      s.z=InverseUnitCellBox[CurrentSystem].az*pos.x+InverseUnitCellBox[CurrentSystem].bz*pos.y+InverseUnitCellBox[CurrentSystem].cz*pos.z;

      s.x-=(REAL)NINT(s.x);
      s.y-=(REAL)NINT(s.y);
      s.z-=(REAL)NINT(s.z);

      if(s.x<0.0) s.x+=1.0;
      if(s.y<0.0) s.y+=1.0;
      if(s.z<0.0) s.z+=1.0;

      pos.x=UnitCellBox[CurrentSystem].ax*s.x+UnitCellBox[CurrentSystem].bx*s.y+UnitCellBox[CurrentSystem].cx*s.z;
      pos.y=UnitCellBox[CurrentSystem].ay*s.x+UnitCellBox[CurrentSystem].by*s.y+UnitCellBox[CurrentSystem].cy*s.z;
      pos.z=UnitCellBox[CurrentSystem].az*s.x+UnitCellBox[CurrentSystem].bz*s.y+UnitCellBox[CurrentSystem].cz*s.z;
      break;
  }

  t.x=rint(((pos.x-ShiftGrid.x)/SizeGrid.x)*(REAL)(NumberOfVDWGridPoints.x));
  t.y=rint(((pos.y-ShiftGrid.y)/SizeGrid.y)*(REAL)(NumberOfVDWGridPoints.y));
  t.z=rint(((pos.z-ShiftGrid.z)/SizeGrid.z)*(REAL)(NumberOfVDWGridPoints.z));
  return t;
}

VECTOR ConvertGridIndexToXYZIndex(INT_VECTOR3 GridIndex)
{
  VECTOR pos;

  pos.x=GridIndex.x*SizeGrid.x/NumberOfVDWGridPoints.x+ShiftGrid.x;
  pos.y=GridIndex.y*SizeGrid.y/NumberOfVDWGridPoints.y+ShiftGrid.y;
  pos.z=GridIndex.z*SizeGrid.z/NumberOfVDWGridPoints.z+ShiftGrid.z;

  return pos;
}

void FloodFillNonRecursive(int seedx,int seedy,int seedz,int BlockingValue)
{
  int i,j,k;
  int w,e;
  int index;

  QueueSize=1;
  Queue[0].x=seedx;
  Queue[0].y=seedy;
  Queue[0].z=seedz;

  do
  {
    i=Queue[0].x;
    j=Queue[0].y;
    k=Queue[0].z;

    Queue[0]=Queue[QueueSize-1];
    QueueSize--;

    if(BlockingGrid[i][j][k]==0)
    {
      for(w=i;w>=0;w--)
        if(BlockingGrid[w][j][k]!=0) break;
      for(e=i;e<=NumberOfVDWGridPoints.x;e++)
        if(BlockingGrid[e][j][k]!=0) break;

      for(i=w+1;i<e;i++)
      {
        BlockingGrid[i][j][k]=BlockingValue;

        index=j+1;
        if(index>NumberOfVDWGridPoints.y) index=0;
        //if(index<=NumberOfVDWGridPoints.y)
        {
          if(BlockingGrid[i][index][k]==0)
          {
            Queue[QueueSize].x=i;
            Queue[QueueSize].y=index;
            Queue[QueueSize].z=k;
            QueueSize++;
          }
        }
        index=j-1;
        if(index<0) index=NumberOfVDWGridPoints.y;
        //if(index>=0)
        {
          if(BlockingGrid[i][index][k]==0)
          {
            Queue[QueueSize].x=i;
            Queue[QueueSize].y=index;
            Queue[QueueSize].z=k;
            QueueSize++;
          }
        }

        index=k+1;
        if(index>NumberOfVDWGridPoints.z) index=0;
        //if(index<=NumberOfVDWGridPoints.z)
        {
          if(BlockingGrid[i][j][index]==0)
          {
            Queue[QueueSize].x=i;
            Queue[QueueSize].y=j;
            Queue[QueueSize].z=index;
            QueueSize++;
          }
        }
        index=k-1;
        if(index<0) index=NumberOfVDWGridPoints.z;
        //if(index>=0)
        {
          if(BlockingGrid[i][j][index]==0)
          {
            Queue[QueueSize].x=i;
            Queue[QueueSize].y=j;
            Queue[QueueSize].z=index;
            QueueSize++;
          }
        }

      }

      // handle periodic boundaries x
      index=w+1;
      if(index>NumberOfVDWGridPoints.x)
      {
        index=0;
        if(BlockingGrid[index][j][k]==0)
        {
          Queue[QueueSize].x=index;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
      }
      index=w-1;
      if(index<0)
      {
        index=NumberOfVDWGridPoints.x;
        if(BlockingGrid[index][j][k]==0)
        {
          Queue[QueueSize].x=index;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
      }
    }
  }
  while(QueueSize>0);
}

int CheckNumber(VECTOR SeedPoint,int ID)
{
  VECTOR C,vec,NewSeedPoint;
  INT_VECTOR3 GridPoint;
  int x,y,z;
  int i,j,k;

  C.x=1.0;
  C.y=0.0;
  C.z=0.0;
  vec.x=UnitCellBox[0].ax*C.x+UnitCellBox[0].bx*C.y+UnitCellBox[0].cx*C.z;
  vec.y=UnitCellBox[0].ay*C.x+UnitCellBox[0].by*C.y+UnitCellBox[0].cy*C.z;
  vec.z=UnitCellBox[0].az*C.x+UnitCellBox[0].bz*C.y+UnitCellBox[0].cz*C.z;

  NewSeedPoint.x=SeedPoint.x+vec.x;
  NewSeedPoint.y=SeedPoint.y+vec.y;
  NewSeedPoint.z=SeedPoint.z+vec.z;
  GridPoint=ConvertXYZPositionToGridIndex(NewSeedPoint);

  for(i=-1;i<=1;i++)
    for(j=-1;j<=1;j++)
       for(k=-1;k<=1;k++)
       {
         x=GridPoint.x+i;
         y=GridPoint.x+j;
         z=GridPoint.x+k;
         if((x>=0&&x<=NumberOfVDWGridPoints.x)&&(y>=0&&y<=NumberOfVDWGridPoints.y)&&(z>=0&&z<=NumberOfVDWGridPoints.z))
             if(BlockingGrid[x][y][z]>2) return BlockingGrid[x][y][z];
       }

  NewSeedPoint.x=SeedPoint.x-vec.x;
  NewSeedPoint.y=SeedPoint.y-vec.y;
  NewSeedPoint.z=SeedPoint.z-vec.z;
  GridPoint=ConvertXYZPositionToGridIndex(NewSeedPoint);
  for(i=-1;i<=1;i++)
    for(j=-1;j<=1;j++)
       for(k=-1;k<=1;k++)
       {
         x=GridPoint.x+i;
         y=GridPoint.x+j;
         z=GridPoint.x+k;
         if((x>=0&&x<=NumberOfVDWGridPoints.x)&&(y>=0&&y<=NumberOfVDWGridPoints.y)&&(z>=0&&z<=NumberOfVDWGridPoints.z))
             if(BlockingGrid[x][y][z]>2) return BlockingGrid[x][y][z];
       }

  C.x=0.0;
  C.y=1.0;
  C.z=0.0;
  vec.x=UnitCellBox[0].ax*C.x+UnitCellBox[0].bx*C.y+UnitCellBox[0].cx*C.z;
  vec.y=UnitCellBox[0].ay*C.x+UnitCellBox[0].by*C.y+UnitCellBox[0].cy*C.z;
  vec.z=UnitCellBox[0].az*C.x+UnitCellBox[0].bz*C.y+UnitCellBox[0].cz*C.z;

  NewSeedPoint.x=SeedPoint.x+vec.x;
  NewSeedPoint.y=SeedPoint.y+vec.y;
  NewSeedPoint.z=SeedPoint.z+vec.z;
  GridPoint=ConvertXYZPositionToGridIndex(NewSeedPoint);
  for(i=-1;i<=1;i++)
    for(j=-1;j<=1;j++)
       for(k=-1;k<=1;k++)
       {
         x=GridPoint.x+i;
         y=GridPoint.x+j;
         z=GridPoint.x+k;
         if((x>=0&&x<=NumberOfVDWGridPoints.x)&&(y>=0&&y<=NumberOfVDWGridPoints.y)&&(z>=0&&z<=NumberOfVDWGridPoints.z))
             if(BlockingGrid[x][y][z]>2) return BlockingGrid[x][y][z];
       }


  NewSeedPoint.x=SeedPoint.x-vec.x;
  NewSeedPoint.y=SeedPoint.y-vec.y;
  NewSeedPoint.z=SeedPoint.z-vec.z;
  GridPoint=ConvertXYZPositionToGridIndex(NewSeedPoint);
  for(i=-1;i<=1;i++)
    for(j=-1;j<=1;j++)
       for(k=-1;k<=1;k++)
       {
         x=GridPoint.x+i;
         y=GridPoint.x+j;
         z=GridPoint.x+k;
         if((x>=0&&x<=NumberOfVDWGridPoints.x)&&(y>=0&&y<=NumberOfVDWGridPoints.y)&&(z>=0&&z<=NumberOfVDWGridPoints.z))
             if(BlockingGrid[x][y][z]>2) return BlockingGrid[x][y][z];
       }


  C.x=0.0;
  C.y=0.0;
  C.z=1.0;
  vec.x=UnitCellBox[0].ax*C.x+UnitCellBox[0].bx*C.y+UnitCellBox[0].cx*C.z;
  vec.y=UnitCellBox[0].ay*C.x+UnitCellBox[0].by*C.y+UnitCellBox[0].cy*C.z;
  vec.z=UnitCellBox[0].az*C.x+UnitCellBox[0].bz*C.y+UnitCellBox[0].cz*C.z;

  NewSeedPoint.x=SeedPoint.x+vec.x;
  NewSeedPoint.y=SeedPoint.y+vec.y;
  NewSeedPoint.z=SeedPoint.z+vec.z;
  GridPoint=ConvertXYZPositionToGridIndex(NewSeedPoint);
  for(i=-1;i<=1;i++)
    for(j=-1;j<=1;j++)
       for(k=-1;k<=1;k++)
       {
         x=GridPoint.x+i;
         y=GridPoint.x+j;
         z=GridPoint.x+k;
         if((x>=0&&x<=NumberOfVDWGridPoints.x)&&(y>=0&&y<=NumberOfVDWGridPoints.y)&&(z>=0&&z<=NumberOfVDWGridPoints.z))
             if(BlockingGrid[x][y][z]>2) return BlockingGrid[x][y][z];
       }


  NewSeedPoint.x=SeedPoint.x-vec.x;
  NewSeedPoint.y=SeedPoint.y-vec.y;
  NewSeedPoint.z=SeedPoint.z-vec.z;
  GridPoint=ConvertXYZPositionToGridIndex(NewSeedPoint);
  for(i=-1;i<=1;i++)
    for(j=-1;j<=1;j++)
       for(k=-1;k<=1;k++)
       {
         x=GridPoint.x+i;
         y=GridPoint.x+j;
         z=GridPoint.x+k;
         if((x>=0&&x<=NumberOfVDWGridPoints.x)&&(y>=0&&y<=NumberOfVDWGridPoints.y)&&(z>=0&&z<=NumberOfVDWGridPoints.z))
             if(BlockingGrid[x][y][z]>2) return BlockingGrid[x][y][z];
       }

  return ID;
}

VECTOR FloodFillNonRecursivePockets(int seedx,int seedy,int seedz,int PocketID,int Offset)
{
  int i,j,k;
  int w,e;
  int index;
  VECTOR dr;
  REAL r;
  int NumberOfVoxels;
  VECTOR PocketCenter,SeedCenter,CurrentCenter;
  INT_VECTOR3 temp;

  temp.x=seedx;
  temp.y=seedy;
  temp.z=seedz;
  SeedCenter=ConvertGridIndexToXYZIndex(temp);

  NumberOfVoxels=0;
  PocketCenter.x=0;
  PocketCenter.y=0;
  PocketCenter.z=0;

  QueueSize=1;
  Queue[0].x=seedx;
  Queue[0].y=seedy;
  Queue[0].z=seedz;

  do
  {
    i=Queue[0].x;
    j=Queue[0].y;
    k=Queue[0].z;

    Queue[0]=Queue[QueueSize-1];
    QueueSize--;

    if(BlockingGrid[i][j][k]==PocketID)
    {
      for(w=i;w>=0;w--)
        if(BlockingGrid[w][j][k]!=PocketID) break;
      for(e=i;e<=NumberOfVDWGridPoints.x;e++)
        if(BlockingGrid[e][j][k]!=PocketID) break;

      for(i=w+1;i<e;i++)
      {
        BlockingGrid[i][j][k]=PocketID+Offset;

        temp.x=i;
        temp.y=j;
        temp.z=k;
        CurrentCenter=ConvertGridIndexToXYZIndex(temp);
        dr.x=CurrentCenter.x-SeedCenter.x;
        dr.y=CurrentCenter.y-SeedCenter.y;
        dr.z=CurrentCenter.z-SeedCenter.z;
        dr=ApplyBoundaryConditionUnitCell(dr);
        r=sqrt(SQR(dr.x)+SQR(dr.y)+SQR(dr.z));


        PocketCenter.x+=(SeedCenter.x+dr.x);
        PocketCenter.y+=(SeedCenter.y+dr.y);
        PocketCenter.z+=(SeedCenter.z+dr.z);
        NumberOfVoxels++;

        index=j+1;
        if(index>NumberOfVDWGridPoints.y) index=0;
        if(BlockingGrid[i][index][k]==PocketID)
        {
          Queue[QueueSize].x=i;
          Queue[QueueSize].y=index;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
        index=j-1;
        if(index<0) index=NumberOfVDWGridPoints.y;
        if(BlockingGrid[i][index][k]==PocketID)
        {
          Queue[QueueSize].x=i;
          Queue[QueueSize].y=index;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
        index=k+1;
        if(index>NumberOfVDWGridPoints.z) index=0;
        if(BlockingGrid[i][j][index]==PocketID)
        {
          Queue[QueueSize].x=i;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=index;
          QueueSize++;
        }
        index=k-1;
        if(index<0) index=NumberOfVDWGridPoints.z;
        if(BlockingGrid[i][j][index]==PocketID)
        {
          Queue[QueueSize].x=i;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=index;
          QueueSize++;
        }

      }

      // handle periodic boundaries x
      index=w+1;
      if(index>NumberOfVDWGridPoints.x)
      {
        index=0;
        if(BlockingGrid[index][j][k]==PocketID)
        {
          Queue[QueueSize].x=index;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
      }
      index=w-1;
      if(index<0)
      {
        index=NumberOfVDWGridPoints.x;
        if(BlockingGrid[index][j][k]==PocketID)
        {
          Queue[QueueSize].x=index;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
      }
    }
  }
  while(QueueSize>0);

  PocketCenter.x/=NumberOfVoxels;
  PocketCenter.y/=NumberOfVoxels;
  PocketCenter.z/=NumberOfVoxels;
  return PocketCenter;
}

REAL FloodFillNonRecursivePocketsRadius(int seedx,int seedy,int seedz,int PocketID,VECTOR SeedCenter)
{
  int i,j,k;
  int w,e;
  int index;
  VECTOR dr;
  REAL r,MaxRadius;
  INT_VECTOR3 temp;
  VECTOR CurrentCenter;

  MaxRadius=0;
  QueueSize=1;
  Queue[0].x=seedx;
  Queue[0].y=seedy;
  Queue[0].z=seedz;

  do
  {
    i=Queue[0].x;
    j=Queue[0].y;
    k=Queue[0].z;

    Queue[0]=Queue[QueueSize-1];
    QueueSize--;

    if(BlockingGrid[i][j][k]==PocketID)
    {
      for(w=i;w>=0;w--)
        if(BlockingGrid[w][j][k]!=PocketID) break;
      for(e=i;e<=NumberOfVDWGridPoints.x;e++)
        if(BlockingGrid[e][j][k]!=PocketID) break;

      for(i=w+1;i<e;i++)
      {
        BlockingGrid[i][j][k]=PocketID+100;

        temp.x=i;
        temp.y=j;
        temp.z=k;
        CurrentCenter=ConvertGridIndexToXYZIndex(temp);
        dr.x=CurrentCenter.x-SeedCenter.x;
        dr.y=CurrentCenter.y-SeedCenter.y;
        dr.z=CurrentCenter.z-SeedCenter.z;
        dr=ApplyBoundaryConditionUnitCell(dr);
        r=sqrt(SQR(dr.x)+SQR(dr.y)+SQR(dr.z));

        r=sqrt(SQR(dr.x)+SQR(dr.y)+SQR(dr.z));
        if(r>MaxRadius) MaxRadius=r;

        index=j+1;
        if(index>NumberOfVDWGridPoints.y) index=0;
        if(BlockingGrid[i][index][k]==PocketID)
        {
          Queue[QueueSize].x=i;
          Queue[QueueSize].y=index;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
        index=j-1;
        if(index<0) index=NumberOfVDWGridPoints.y;
        if(BlockingGrid[i][index][k]==PocketID)
        {
          Queue[QueueSize].x=i;
          Queue[QueueSize].y=index;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
        index=k+1;
        if(index>NumberOfVDWGridPoints.z) index=0;
        if(BlockingGrid[i][j][index]==PocketID)
        {
          Queue[QueueSize].x=i;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=index;
          QueueSize++;
        }
        index=k-1;
        if(index<0) index=NumberOfVDWGridPoints.z;
        if(BlockingGrid[i][j][index]==PocketID)
        {
          Queue[QueueSize].x=i;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=index;
          QueueSize++;
        }
      }

      // handle periodic boundaries x
      index=w+1;
      if(index>NumberOfVDWGridPoints.x)
      {
        index=0;
        if(BlockingGrid[index][j][k]==PocketID)
        {
          Queue[QueueSize].x=index;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
      }
      index=w-1;
      if(index<0)
      {
        index=NumberOfVDWGridPoints.x;
        if(BlockingGrid[index][j][k]==PocketID)
        {
          Queue[QueueSize].x=index;
          Queue[QueueSize].y=j;
          Queue[QueueSize].z=k;
          QueueSize++;
        }
      }
    }
  }
  while(QueueSize>0);
  return MaxRadius;
}



int AnyRemainingPockets(int *seedx,int *seedy,int *seedz,int PocketID)
{
  int i,j,k;

  for(i=0;i<=NumberOfVDWGridPoints.x;i++)
    for(j=0;j<=NumberOfVDWGridPoints.y;j++)
      for(k=0;k<=NumberOfVDWGridPoints.z;k++)
        if(BlockingGrid[i][j][k]==PocketID)
        {
          *seedx=i;
          *seedy=j;
          *seedz=k;
          return TRUE;
        }
  return FALSE;
}

VECTOR *PocketsCenterOfMass;
REAL *PocketsRadius;

VECTOR DoubleCenters[1024];
int NumberOfDoubleCenters;
VECTOR StoredCenters[1024];
VECTOR FinalCenters[1024];
int CountFinalCenters[1024];
int NumberOfFinalCenters;

void ClassifyPockets(void)
{
  int i,j;
  int seedx,seedy,seedz;
  int PocketID;
  VECTOR center,dr,v1,v2,s;
  REAL radius,r;
  int CheckOverlap,ID;
  INT_VECTOR3 bl;

  seedx=seedy=seedz=0;

  PocketID=11;
  while(AnyRemainingPockets(&seedx,&seedy,&seedz,0))
  {
    fprintf(stderr, "Pocket ID: %d\n",PocketID);
    FloodFillNonRecursive(seedx,seedy,seedz,PocketID++);
  };

  PocketsCenterOfMass=(VECTOR*)calloc(PocketID,sizeof(VECTOR));
  PocketsRadius=(REAL*)calloc(PocketID,sizeof(REAL));

  NumberOfDoubleCenters=0;
  for(i=11;i<PocketID;i++)
  {
    AnyRemainingPockets(&seedx,&seedy,&seedz,i);
    center=FloodFillNonRecursivePockets(seedx,seedy,seedz,i,50);

    if(CheckIfPointIsInUnitCell(center))
      DoubleCenters[NumberOfDoubleCenters++]=center;

  }

  NumberOfFinalCenters=0;
  fprintf(stderr, "NumberOfDoubleCentersL %d\n",NumberOfDoubleCenters);
  for(i=0;i<NumberOfDoubleCenters;i++)
  {
    v1=DoubleCenters[i];

    CheckOverlap=FALSE;
    for(j=0;j<NumberOfFinalCenters;j++)
    {
      v2=StoredCenters[j];
      dr.x=v1.x-v2.x;
      dr.y=v1.y-v2.y;
      dr.z=v1.z-v2.z;
      dr=ApplyBoundaryConditionUnitCell(dr);
      r=sqrt(SQR(dr.x)+SQR(dr.y)+SQR(dr.z));
      if(r<2.0)
      {
        CheckOverlap=TRUE;
        break;
      }
    }
    if(CheckOverlap==FALSE)
    {
       StoredCenters[NumberOfFinalCenters]=DoubleCenters[i];
       FinalCenters[NumberOfFinalCenters]=DoubleCenters[i];
       CountFinalCenters[NumberOfFinalCenters]++;
       NumberOfFinalCenters++;
    }
    else
    {
       FinalCenters[j].x+=DoubleCenters[j].x+dr.x;
       FinalCenters[j].y+=DoubleCenters[j].y+dr.y;
       FinalCenters[j].z+=DoubleCenters[j].z+dr.z;
       CountFinalCenters[j]++;
    }
  }
  fprintf(stderr, "NumberOfFinalCenters: %d\n",NumberOfFinalCenters);
  for(i=0;i<NumberOfFinalCenters;i++)
  {
    center.x=FinalCenters[i].x/CountFinalCenters[i];
    center.y=FinalCenters[i].y/CountFinalCenters[i];
    center.z=FinalCenters[i].z/CountFinalCenters[i];
/*
    s.x=InverseUnitCellBox[CurrentSystem].ax*center.x+InverseUnitCellBox[CurrentSystem].bx*center.y+InverseUnitCellBox[CurrentSystem].cx*center.z;
    s.y=InverseUnitCellBox[CurrentSystem].ay*center.x+InverseUnitCellBox[CurrentSystem].by*center.y+InverseUnitCellBox[CurrentSystem].cy*center.z;
    s.z=InverseUnitCellBox[CurrentSystem].az*center.x+InverseUnitCellBox[CurrentSystem].bz*center.y+InverseUnitCellBox[CurrentSystem].cz*center.z;
    fprintf(stderr, "%g %g %g\n",s.x,s.y,s.z);
*/
    center=ConvertPositionToVTKPosition(center);
    fprintf(stderr, "%g %g %g\n",center.x,center.y,center.z);
  }


  fprintf(stderr, "\n\n");

  for(i=0;i<NumberOfFinalCenters;i++)
  {
    center.x=FinalCenters[i].x/CountFinalCenters[i];
    center.y=FinalCenters[i].y/CountFinalCenters[i];
    center.z=FinalCenters[i].z/CountFinalCenters[i];

    bl=ConvertXYZPositionToGridIndex(center);
    if((bl.x>=0)&&(bl.x<=NumberOfVDWGridPoints.x)&&
       (bl.y>=0)&&(bl.y<=NumberOfVDWGridPoints.y)&&
       (bl.z>=0)&&(bl.z<=NumberOfVDWGridPoints.z))
    {
    ID=BlockingGrid[bl.x][bl.y][bl.z];
    if(ID>2)
    {

    s.x=InverseUnitCellBox[CurrentSystem].ax*center.x+InverseUnitCellBox[CurrentSystem].bx*center.y+InverseUnitCellBox[CurrentSystem].cx*center.z;
    s.y=InverseUnitCellBox[CurrentSystem].ay*center.x+InverseUnitCellBox[CurrentSystem].by*center.y+InverseUnitCellBox[CurrentSystem].cy*center.z;
    s.z=InverseUnitCellBox[CurrentSystem].az*center.x+InverseUnitCellBox[CurrentSystem].bz*center.y+InverseUnitCellBox[CurrentSystem].cz*center.z;
    fprintf(stderr, "%g %g %g ",s.x,s.y,s.z);

      radius=FloodFillNonRecursivePocketsRadius(bl.x,bl.y,bl.z,ID,center);
      fprintf(stderr, "%d %g\n",i,radius);
    }

    }
  }
  exit(0);
}


REAL GetGridEnergy(int typeA,int x0,int y0,int z0)
{
  int i,j,k;
  REAL value;
  REAL X[64],a[64];

  // retrieve the grid value and the derivatives
  for(i=0;i<8;i++)
  {
    X[0+i*8]=VDWGrid[typeA][x0][y0][z0][i];
    X[1+i*8]=VDWGrid[typeA][x0+1][y0][z0][i];
    X[2+i*8]=VDWGrid[typeA][x0][y0+1][z0][i];
    X[3+i*8]=VDWGrid[typeA][x0+1][y0+1][z0][i];
    X[4+i*8]=VDWGrid[typeA][x0][y0][z0+1][i];
    X[5+i*8]=VDWGrid[typeA][x0+0][y0][z0+1][i];
    X[6+i*8]=VDWGrid[typeA][x0][y0+1][z0+1][i];
    X[7+i*8]=VDWGrid[typeA][x0+1][y0+1][z0+1][i];
  }

  for (i=0;i<64;i++)
  {
    a[i]=(double)(0.0);
    for (j=0;j<64;j++)
      a[i]+=Coeff[i][j]*X[j];
  }

  // energy
  value=0.0;
  for (i=0;i<4;i++)
    for (j=0;j<4;j++)
      for (k=0;k<4;k++)
        value+=a[i+4*j+16*k]*pow(0.0,i)*pow(0.0,j)*pow(0.0,k);

  return value;
}

void BlockingVDWGrid(void)
{
  int i,j,k,l;
  REAL energy;

  // return if blocking the grids is not wanted
  if(!BlockEnergyGrids) return;

  // return if no grids are loaded
  if(!UseTabularGrid) return;


  // Allocate the memory for this grid
  BlockingGrid=(char***)calloc(NumberOfVDWGridPoints.x+1,sizeof(char**));
  for(i=0;i<=NumberOfVDWGridPoints.x;i++)
  {
    BlockingGrid[i]=(char**)calloc(NumberOfVDWGridPoints.y+1,sizeof(char*));
    for(j=0;j<=NumberOfVDWGridPoints.y;j++)
      BlockingGrid[i][j]=(char*)calloc(NumberOfVDWGridPoints.z+1,sizeof(char));
  }

  // initialize the queue for the flood-fill algorithm
  QueueSize=0;
  Queue=(INT_VECTOR3*)calloc((NumberOfVDWGridPoints.x+1)*(NumberOfVDWGridPoints.y+1)*(NumberOfVDWGridPoints.z+1),
                             sizeof(INT_VECTOR3));

  fprintf(stderr, "BlockEnergyGridOverlapCriteria: %g\n",BlockEnergyGridOverlapCriteria);

  // patch grid: set blocking zones to 'overlap'
  for(l=0;l<NumberOfPseudoAtoms;l++)
  {
    if(VDWGrid[l])
    {
      // set energy-favorable regions to '0', overlap regions to '1'
      for(i=0;i<=NumberOfVDWGridPoints.x;i++)
        for(j=0;j<=NumberOfVDWGridPoints.y;j++)
          for(k=0;k<=NumberOfVDWGridPoints.z;k++)
          {
            energy=VDWGrid[l][i][j][k][0];
            if(energy<BlockEnergyGridOverlapCriteria)
              BlockingGrid[i][j][k]=0;
            else
              BlockingGrid[i][j][k]=1;
          }

       // before: low energy regions set to '0', high energy regions set to '1'
       // after: low energy regions of pores set to '2', high energy regions to '1',
       //        therefore the remaining values of '0' are considered as 'pockets'
       for(i=0;i<NumberOfGridSeeds;i++)
         FloodFillNonRecursive(GridSeeds[i].x,GridSeeds[i].y,GridSeeds[i].z,2);

       for(i=0;i<=NumberOfVDWGridPoints.x;i++)
         for(j=0;j<=NumberOfVDWGridPoints.y;j++)
           for(k=0;k<=NumberOfVDWGridPoints.z;k++)
           {
             // if the current voxel is a pocket and pockets are set to 'blocked' or
             // if the current voxel is a pore and pores are set to 'blocked', then block the voxel
             // (pores can also be blocked to visualize just the pockets in VTK)
             if(((BlockingGrid[i][j][k]==0)&&(BlockGridPockets))||((BlockingGrid[i][j][k]==2)&&(BlockGridPores)))
             {
               VDWGrid[l][i][j][k][0]=EnergyOverlapCriteria;
               VDWGrid[l][i][j][k][1]=EnergyOverlapCriteria;
               VDWGrid[l][i][j][k][2]=EnergyOverlapCriteria;
               VDWGrid[l][i][j][k][3]=EnergyOverlapCriteria;
               VDWGrid[l][i][j][k][4]=0.0;
               VDWGrid[l][i][j][k][5]=0.0;
               VDWGrid[l][i][j][k][6]=0.0;
               VDWGrid[l][i][j][k][7]=0.0;
             }
           }
    }
  }

  ClassifyPockets();

  int count[200];
  int total_count=0;

  for(l=0;l<50;l++)
  {
    count[l]=0;
    for(i=0;i<=NumberOfVDWGridPoints.x;i++)
      for(j=0;j<=NumberOfVDWGridPoints.y;j++)
        for(k=0;k<=NumberOfVDWGridPoints.z;k++)
          count[(int)BlockingGrid[i][j][k]]++;
    total_count+=count[l];
    if(count[l]>0) fprintf(stderr, "count: %d -> %d\n",l,count[l]);
  }
  fprintf(stderr, "total: %d %d\n",(1+NumberOfVDWGridPoints.x)*(1+NumberOfVDWGridPoints.y)*(1+NumberOfVDWGridPoints.z),total_count);


  fprintf(stderr, "exit\n");

  free(Queue);
}


static int versionNumber=1;

void WriteRestartGrids(FILE *FilePtr)
{
  REAL Check;

  fwrite(&versionNumber,sizeof(int),1,FilePtr);

  fwrite(&SpacingVDWGrid,1,sizeof(REAL),FilePtr);
  fwrite(&SpacingCoulombGrid,1,sizeof(REAL),FilePtr);
  fwrite(&NumberOfGrids,1,sizeof(int),FilePtr);
  fwrite(GridTypeList,NumberOfGrids,sizeof(int),FilePtr);

  Check=123456789.0;
  fwrite(&Check,1,sizeof(REAL),FilePtr);
}

void AllocateGridMemory(void)
{

  GridTypeList=(int*)calloc(NumberOfGrids,sizeof(int));
  VDWGrid=(float*****)calloc(NumberOfPseudoAtoms,sizeof(float****));
}

void ReadRestartGrids(FILE *FilePtr)
{
  REAL Check;
  int readversionNumber=0;

  fread(&readversionNumber,sizeof(int),1,FilePtr);
  if(readversionNumber > versionNumber)
  {
    fprintf(stderr,"Upgrade to last version of RASPA to read binary restart-file");
    exit(-1);
  }

  fread(&SpacingVDWGrid,1,sizeof(REAL),FilePtr);
  fread(&SpacingCoulombGrid,1,sizeof(REAL),FilePtr);
  fread(&NumberOfGrids,1,sizeof(int),FilePtr);

  AllocateGridMemory();
  fread(GridTypeList,NumberOfGrids,sizeof(int),FilePtr);

  if(Framework[0].FrameworkModel==GRID)
  {
    CurrentSystem=0;
    ReadVDWGrid();
    if(ChargeMethod!=NONE)
      ReadCoulombGrid();
  }

  fread(&Check,1,sizeof(REAL),FilePtr);
  if(fabs(Check-123456789.0)>1e-10)
  {
    fprintf(stderr, "Error in binary restart-file (ReadRestartGrids)\n");
    ContinueAfterCrash=FALSE;
  }
}