---
license: cc-by-4.0
pretty_name: COSMOBridge — data, frozen predictions and DFT outputs
size_categories:
  - n<1K
tags:
  - chemistry
  - ionic-liquids
  - thermodynamics
  - activity-coefficients
  - molecular-property-prediction
  - cosmo-rs
  - dft
---

# COSMOBridge — data, frozen predictions and DFT outputs

Archive accompanying *"COSMOBridge: Bridging 2D Molecular Graphs and 3D Electrostatic
Surfaces for Ionic Liquid Thermodynamic Property Prediction"* (submitted to the
*Journal of Chemical Information and Modeling*).

Source code: <https://github.com/taminulislam/COSMOBridge> (MIT licence).
Archive DOI: [10.57967/hf/11424](https://doi.org/10.57967/hf/11424).
This repository is the permanent record of the data, models and predictions behind the
paper's tables and figures.

> **The predictions in `predictions/` are deposited before the validation measurements
> described in Section 5.3 of the paper are made.** Their purpose is to fix the model's
> output so that those measurements score predictions made *ex ante*. Please do not
> amend that directory after the measurements begin.

## Contents

| Path | What it is | Used by |
|---|---|---|
| `dataset/` | the curated 28-ionic-liquid dataset, split by ionic-liquid identity into 19 train (152 rows) / 4 validation (32) / 5 test (39), plus `split_info.json` naming the ILs in each split | Table 1, §2.2, all training |
| `predictions/candidates_110_frozen_ranking.csv` | the full 110-candidate virtual screen, per-seed means and standard deviations, in original units | Table 7, Figure 7 |
| `predictions/test_set_predictions.npz` | held-out test-set predictions: 5 COSMOBridge seeds, the Chemprop baseline, the fusion path, and the targets | Tables 3 and 4, the bootstrap tests |
| `predictions/top20_candidates.csv` | the 20 candidates carried forward to DFT | SI Table S2 |
| `dft/nwchem_outputs/` | raw NWChem B3LYP/def2-SVP + COSMO outputs, 40 single points covering 16 unique ions | SI Table S2 |
| `dft/nwchem_inputs/`, `dft/geometries/` | the inputs and GFN2-xTB geometries those runs used | reproduction |
| `checkpoints/` | trained weights for the reported models | Table 3 |
| `analysis/*.json` | outputs of the bootstrap and seed-matched baseline runs, as reported in the paper | §4.1, Table 3 |
| `experimental/` | characterization report and figures for the two synthesized salts | §5.2, SI §S2 |

## Reproducing the analyses

All code lives in the GitHub repository above; this archive holds only data and model
weights. The scripts `scripts/revision/b5_chemprop_multiseed.py` (Chemprop over the five
shared seeds, Table 3) and `scripts/revision/b6_cluster_bootstrap.py` (row-level and
IL-level bootstrap, Section 4.1) read `dataset/` and `predictions/` from here and
reproduce `analysis/b5_chemprop_multiseed.json` and `analysis/b6_cluster_bootstrap.json`.
`analysis/c1_official_bootstrap.json` is the original row-level bootstrap that the paper
reports alongside them.

## Notes on the data

- **The 39 test rows are 8 temperatures of each of 5 ionic liquids and are not
  independent.** `b6_cluster_bootstrap.py` resamples at both levels; the IL-level
  interval is the conservative one.
- **The DFT solvation energies are a null result.** They are the
  `(electrostatic) solvation energy` line of each NWChem COSMO block, reported as
  `E_sol - E_gas`, and they do **not** correlate with the screen's ranking
  (Spearman rho = -0.28, p = 0.23). Do not read them as support for the ranking.
- **Activity coefficients are plain gamma, not ln gamma**, at `x1 = 0.5` and the stated
  temperature. The identity `G^E = RT(x1 ln g1 + x2 ln g2)` closes to within
  0.09 kcal/mol on this footing.
- The dataset grid is complete except for EMIMOAc at 323.15 K: 223 rows, not 224.
- No data are withheld.

## Citation

```bibtex
@article{cosmobridge2026,
  author  = {Ahmed, Khaled and Islam, Taminul and Acquah, Alex and Achinivu-Ibagere, Ezinne C.},
  title   = {{COSMOBridge}: Bridging {2D} Molecular Graphs and {3D} Electrostatic
             Surfaces for Ionic Liquid Thermodynamic Property Prediction},
  journal = {Journal of Chemical Information and Modeling},
  year    = {2026},
  note    = {Submitted}
}
```