domain stringclasses 7
values | sub_source stringclasses 15
values | coding_subclass stringclasses 6
values | messages listlengths 2 24 | tools listlengths 1 94 ⌀ |
|---|---|---|---|---|
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a polycyclic aromatic molecule that can be described by the following electronic states and processes (all populations are dimensionless fractions of the total molecular ensemble):\n\n- Ground electronic state \\(S_{0}\\).\n- First excited singlet state \\(S_{1}\\) (en... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A water‑in‑oil‑in‑water (W/O/W) double emulsion is prepared to encapsulate a water‑soluble active ingredient (AI). The inner aqueous phase (phase W₁) contains the AI at an initial concentration C₀ (kg m⁻³). The middle oil phase (phase O) is a molten lipid with viscosity η_O = 0... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A solid quartz substrate is coated with a uniform phospholipid film of initial dry thickness \\(h_0\\) and area \\(A\\). The film is exposed to pure water at \\(25^{\\circ}\\text{C}\\). Water penetrates the film by diffusion and simultaneously induces a structural re‑organizati... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A rigid polycyclic framework possesses C₃ᵥ point‑group symmetry in the gas phase. The molecule contains three symmetry‑related bridgehead carbon atoms (the axial positions) and six symmetry‑related peripheral carbon atoms on the aromatic rings (the equatorial positions). In a s... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A monoclinic crystal belonging to space group **P2₁/n** was measured with Mo Kα radiation (λ = 0.71073 Å). The unit‑cell parameters are a = 11.3448 Å, b = 18.6100 Å, c = 19.3282 Å, β = 97.297°. A total of **41 058** reflections were recorded, of which **9 360** are independent ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider the benzene nucleus as a regular hexagon whose six vertices represent the six hydrogen‑bearing carbon atoms. The symmetry group of the unsubstituted molecule is the full dihedral group D_{6h} (order 12), whose rotational and reflection operations permute the vertices.\... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A spherical fluid lipid vesicle of radius \\(R\\) is aspirated by a micropipette so that a uniform membrane tension \\(\\sigma\\) is applied. The tension is increased at a constant loading rate \\(r = d\\sigma/dt\\) (units mN m\\(^{-1}\\) s\\(^{-1}\\)). Rupture of the membrane ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A first‑generation poly(amidoamine) (PAMAM) dendrimer with an ethylenediamine core (the “parent” dendrimer) is functionalized in three different ways to give three distinct samples:\n\n1. Sample A – retains the primary amine termini (designated E1.NH₂).\n2. Sample B – each prim... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A linear triatomic molecule ABX is photodissociated at a wavelength of 288 nm to produce an excited atomic fragment X* (in a well‑characterized electronic state) and a diatomic fragment AB. In a velocity‑map imaging experiment employing a direct‑current (DC) “slice” technique, ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A chemical‑looping (CL) scheme is proposed for the simultaneous production of nitric oxide (NO) and hydrogen (H₂) from ammonia (NH₃) using a solid metal‑oxide oxygen carrier (OC). The cycle consists of two steps:\n\n1. **Reduction (R)** – NH₃ reduces the fully oxidised carrier ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a series of photoactive molecular rotors that undergo excited‑state relaxation described by a tri‑exponential decay with time constants τ₁, τ₂, τ₃. The fastest component τ₁ is experimentally observed to be independent of the solvent viscosity η, whereas τ₂ and τ₃ incre... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A low‑symmetry organosilicon donor (D) forms a charge‑transfer (CT) complex with tetracyanoethylene (TCNE, A). The solid CT complex crystallises in the triclinic space group *P*1 with the following unit‑cell parameters (determined by single‑crystal X‑ray diffraction):\n\n- a = ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a molecular crystal composed of alternating aromatic and perfluoroaromatic layers that are held together primarily by two distinct types of intermolecular contacts:\n\n1. **π–π stacking interactions** between parallel aromatic rings.\n2. **Weak van der Waals contacts**... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a homogeneous aqueous reaction in which a tetravalent metal ion M4+ oxidizes a dicarboxylic substrate S (formula C3H4O4) under constant temperature and excess water. Two competing overall pathways are observed:\\n\\n1. Recombination pathway – a direct reaction of M4+ w... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A spherical bimetallic nanoparticle of radius $R = 2.5\\;{\\rm nm}$ consists of palladium (Pd) and gold (Au) atoms. The total number of atoms in the particle is $N \\approx 10^{4}$. The overall atomic fraction of Au in the particle is $x_{\\rm Au}^{\\rm bulk}=0.30$. The alloy c... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a planar aromatic chromophore bearing a nitro substituent that can rotate about the C–N bond, giving a dihedral angle θ between the nitro plane and the aromatic ring. In the electronic ground state the molecule samples a distribution of θ values; the equilibrium geomet... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider the gas‑phase reaction of a silyl radical SiH₃· with a series of saturated silanes SiₙH₂ₙ₊₂ (n = 1–4). For each silane, two competing elementary pathways are possible:\n\n1. Hydrogen abstraction:\n SiH₃· + SiₙH₂ₙ₊₂ → SiH₄ + SiₙH₂ₙ₊₁·\n\n2. Silicon‑for‑hydrogen substi... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a family of ionic surfactants in which both the cationic headgroup and the anionic counter‑ion bear a single linear alkyl chain. The cationic headgroup is a 1‑alkyl‑3‑methylimidazolium (CₙH₂ₙ₊₁‑mim⁺) and the anion is an alkyl‑sulfonate (CₘH₂ₘ₊₁SO₃⁻). The total number o... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Two identical atoms (either bosons or fermions) are confined in a trap such that their center‑of‑mass wavefunctions are described by normalized spatial orbitals ϕ₁( r ) and ϕ₂( r ). The atoms possess a single electric‑dipole allowed transition |g⟩ ↔ |e⟩ with transition dipole m... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a fed‑batch cultivation of *Saccharomyces cerevisiae* on glucose in which the specific growth rate follows a Monod‑type expression with substrate inhibition\n\n\\[\\mu(S)=\\frac{\\mu_{\\max}\\,S}{K_s+S+S^{2}/K_i},\\]\n\nand ethanol produced stoichiometrically with yiel... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A nanotribology laboratory is investigating the frictional behavior of a thin organic film that exhibits two distinct crystalline domains, Domain I and Domain II. Each domain presents a different terminal functional group at the free surface, leading to distinct interfacial she... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a weakly bound van der Waals dimer composed of two identical diatomic molecules AB (each with an equilibrium intramolecular bond length r₀ = 1.10 Å). The dimer equilibrium centre‑to‑centre separation is R₀ = 3.50 Å. A collision with a highly charged ion removes three e... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A monoclinic crystal (space group *P2₁/c*) contains three crystallographically inequivalent bromine sites (Br₁, Br₂, Br₃), each with nuclear spin I = 3/2. The ⁸¹Br nuclear quadrupole resonance (NQR) frequencies were measured as a function of temperature T (in kelvin) on a powde... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A cohort of 325 patients with cytogenetically normal acute myeloid leukemia (CN‑AML) was prospectively followed for overall survival (OS). For each patient the following baseline variables were recorded \n| Variable | Type | Description |\n|----------|------|-------------|\n| ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A family of inorganic–organic compounds with the general formula NaOR (R = ethyl, n‑propyl, n‑butyl, n‑pentyl) crystallizes in a tetragonal lattice. Powder X‑ray diffraction data reveal systematic absences consistent with two possible space groups, P4_2nm and P4/nmm. The Na and... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A reversed‑phase HPLC column is used to separate a permanently protonated basic analyte **B⁺** (e.g., a phenyl‑trimethyl‑ammonium derivative). The mobile phase consists of water with a low percentage of an organic modifier (5 % v/v acetonitrile) and a variable concentration **C... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a wurtzite oxide MX₂ (M = metal, X = O) that exhibits two low‑index non‑polar surfaces, denoted (10‑10) and (11‑20). For each surface you have constructed a symmetric slab containing four MX₂ bilayers (i.e., eight M atoms and eight X atoms per slab) with a surface area... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A concerted electrocyclization reaction proceeds via a pentadienyl cation intermediate that can exist in two rapidly interconverting conformers, C₁ (non‑reactive) and C₂ (reactive). The interconversion is governed by first‑order rate constants k₁₂ and k₂₁, and only C₂ undergoes... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A mannopyranosyl donor bearing a good leaving group (triflate) reacts with an alcohol acceptor to give an α‑mannopyranoside. Two mechanistic pathways are possible:\n\n1. **Associative (SN2‑like) pathway:** The nucleophile attacks the anomeric carbon as the leaving group departs... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A series of stilbene derivatives bearing a single hydroxy substituent at either the meta (3‑) or para (4‑) position have been investigated in acetonitrile (dielectric constant ε = 36, ET(30) = 56.0 kcal mol⁻¹, hydrogen‑bond acceptor parameter β = 0.40). The following spectrosco... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A dense supercritical fluid at temperature \\(T = 314\\;\\text{K}\\) and mass density \\(\\rho = 0.84\\;\\text{g cm}^{-3}\\) is subjected to a short pulse of high‑energy radiation that creates ion pairs uniformly throughout the sample. The primary ionization event produces, on ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A bis‑phosphazene compound (B) is investigated as a “proton sponge”. High‑level DFT calculations give a gas‑phase proton affinity (PA) of **274 kcal mol⁻¹** for the reaction\n\nB (g) + H⁺ → BH⁺ (g).\n\nIn the conjugate acid BH⁺ an intramolecular hydrogen bond is formed, whose s... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A family of hexagonal aluminosilicate framework minerals can be represented by the general formula A_x B_{1-x} B_4 C_2 O_11, where the A‑site is occupied by a divalent cation (Ca²⁺) and the B‑site by a monovalent cation (Na⁺). The end‑members are\n- CAS: CaAl₄Si₂O₁₁ (pure Ca on... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A semi‑flexible organic ligand **L** consists of an anthracene core bearing two 1‑H‑imidazolyl groups at the 9‑ and 10‑positions. Rotation about the C–C bonds linking the imidazole rings to the anthracene allows **L** to adopt either a *cis* (both imidazoles on the same side of... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a three‑dimensional fluid composed of $N$ identical spherical particles each bearing a permanent point dipole moment $\\boldsymbol{\\mu}= \\mu\\,\\mathbf{u}$, where $\\mathbf{u}$ is a unit vector indicating the dipole orientation. The particles interact via a Lennard‑J... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A 2‑carbon vinyl ether radical (CH₂=CH–O•) is formed by H‑atom abstraction from vinyl methyl ether (CH₂=CH–OCH₃). The radical can react with molecular oxygen to give a peroxy adduct (CH₂=CH–OO•) that may either be stabilized, undergo back‑reaction to reactants, or isomerize to ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A Schiff‑base molecule contains an intramolecular O–H···N hydrogen bond that can exist in two tautomeric forms:\n\n- **Tautomer I** – the proton is bound to the phenolic oxygen (O‑H···N).\n- **Tautomer II** – the proton is transferred to the imine nitrogen (O···H‑N).\n\nIn solu... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A divalent metal ion **M²⁺** is studied in aqueous solutions that contain a binary mixture of sodium hydroxide (NaOH) and sodium perchlorate (NaClO₄). All experiments are performed at 25 °C and at a fixed total ionic strength **I = 3.0 mol kg⁻¹** (the ionic strength is maintain... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A copper(II) catalyst mediates the reaction of an aryl diazonium tetrafluoroborate (Ar‑N₂⁺ BF₄⁻) with a bifunctional allylic diol (HO‑CH₂‑CH(OH)‑CH₂‑O‑CH₂‑CH=CH₂) in the presence of ammonium thiocyanate (NH₄SCN). Two competing pathways are observed:\n\n1. **Thiocyanato‑arylatio... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a single‑molecule junction in which a planar organic molecule is connected to two semi‑infinite graphene electrodes. The molecule can be attached to each electrode either (i) via a covalent σ‑bond formed by a functional group that creates a sp³‑type hybridization on th... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a diblock copolymer consisting of an amorphous polystyrene block (A) and a side‑chain liquid‑crystalline block (B) bearing mesogenic groups that can form a smectic A phase. The total degree of polymerization is N = N_A + N_B with volume fractions f_A and f_B (f_A + f_B... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A series of copper‑based catalysts supported on titanium dioxide are investigated for the oxidation of carbon monoxide (CO + ½ O₂ → CO₂). The catalysts differ in three key surface characteristics:\n\n1. **Copper oxidation state distribution** – a fraction *f*₁ of surface copper... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A molecular dynamics (MD) study investigates the evaporation of a thin water film placed on a planar carbonaceous substrate. Two substrates are considered:\n\n* **Substrate A (pristine graphene):** a single atomic layer of carbon atoms arranged in a perfect hexagonal lattice wi... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A family of organocatalysts based on pyridine N‑oxide (single‑N‑oxide) and 2,2′‑bipyridine N,N′‑dioxide (dual‑N‑oxide) has been investigated computationally. Gas‑phase electronic energies (including zero‑point vibrational corrections) were obtained at the B3LYP/6‑311+G** level ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A research group has synthesized a series of hollow nanorod electrocatalysts for the hydrogen evolution reaction (HER) based on iron phosphide (FeP) and its nickel‑doped derivatives, Fe₁₋ₓNiₓP (with x = 0, 0.05, 0.10, 0.15). All samples retain the same hollow rod morphology and... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider three octupolar metal complexes of D₃ symmetry, each comprising a central metal ion M coordinated by three identical bipyridyl ligands. The ligands contain a conjugated bridge of N phenylene units (N = 2, 3, 4) terminated by a donor group D (‑NR₂, ‑OMe, or ‑N=CH). The ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a colloidal suspension of spherical ferromagnetic nanoparticles of radius \\(R = 7.5\\;\\text{nm}\\) coated with a non‑magnetic surfactant layer of thickness \\(\\delta = 2\\;\\text{nm}\\). Each particle has saturation magnetization \\(M_s\\) and uniaxial anisotropy co... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A series of cationic Rh(I) complexes of the general formula \\([\\{\\rm Rh\\}(PPh_{3})_{2}(L)\\]^{+}X^{-}\\) have been prepared, where the neutral ligand \\(L\\) is either norbornadiene (nbd) or an \\(\\eta^{6}\\)-bound arene, and the counter‑anion \\(X^{-}\\) is one of the fol... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a planar polyatomic molecule whose vibrational normal modes can be approximated as independent harmonic oscillators with fundamental frequencies {ν₁, ν₂, …, ν_N}.\n\n1. **State density calculation**\n(a) Derive an approximate expression for the vibrational state densit... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "You are given a regional geochemical dataset consisting of eight surface‑soil samples. For each sample you have the planar coordinates (in km) and the measured concentrations (in ppm) of three trace elements (A, B, C) that are considered potential indicators of a buried mineral... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a system in which a linear cationic polymer P (degree of polymerization N, linear charge density λ_P [e⁻ nm⁻¹]) can electrostatically bind to an anionic supramolecular nanofiber F (rod‑like, length L, linear charge density λ_F [e⁻ nm⁻¹], persistence length ℓ_p). Bindin... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A porous solid is modeled as a collection of independent, open cylindrical capillaries whose radii $r$ are distributed according to an unknown density function $f(r)$ (with $\\\\int_{0}^{\\\\infty} f(r)\\\\,dr = 1$). At temperature $T$ a non‑polar adsorbate of molar volume $V_m... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A biodegradable injectable hydrogel is formed in situ by mixing two aqueous polymer solutions:\n\n- **Polymer A**: hyaluronic acid (HA) backbone (average molecular weight 1.0 MDa) functionalized with aldehyde groups (–CHO) at a degree of substitution (DS) of 10 % (i.e., 0.10 mo... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a quasi‑two‑dimensional antiferromagnet consisting of spin‑S=2 magnetic ions arranged on a perfect triangular lattice with nearest‑neighbour Heisenberg exchange J>0. A small concentration x (0<x≪1) of these magnetic sites are randomly replaced by non‑magnetic vacancies... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A series of five para‑substituted organometallic complexes of the type \n\n\\[\\mathrm{[M(CO)_5=C(OCH_3)CH=CHC_6H_4X]}\\qquad (X = \\text{p‑OMe, p‑Me, H, p‑Cl, p‑NO_2})\\]\n\nundergo alkaline hydrolysis in a 1 : 1 (v/v) water–acetonitrile mixture. The reaction is first order i... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A series of binary liquid mixtures is prepared from a strongly hydrogen‑bonding component A and a non‑hydrogen‑bonding, weakly interacting component B. The mole fraction of A is denoted by $x$ (so that $x=1$ corresponds to the pure hydrogen‑bonded liquid).\n\nUsing field‑cyclin... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A continuous tray distillation column separates a binary mixture of components A and B. The column has 30 theoretical stages, with a total reflux ratio of 1.5. The top product (distillate) composition is required to be 95 mol % A, while the bottom product (bottoms) composition ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A mononuclear iron complex undergoes a reversible Fe(III)/Fe(II) redox couple. In the oxidized state the iron is coordinated by four identical ligands L, forming an FeL₄ tetrahedral site. Two different ligand sets are considered:\n\n- **Set A:** L = thiolate (S⁻), with an Fe–S ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A layered silicate host can incorporate trivalent aluminum cations (Al³⁺) from an aqueous solution. Within the interlayer space, Al³⁺ may undergo hydrolysis and polymerization to form a polyoxometalate (POM) of Keggin topology, specifically an Al₁₃ cluster that can be regarded ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Two monoclinic crystals of the formula C₁₂H₁₀X₂ (X = Cl or Br) are isomorphous, each containing four molecules per unit cell. The crystallographic data are as follows (all lengths in Å, angles in degrees):\n\n| Parameter | Cl‑compound | Br‑compound |\n|-----------|-------------... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a heterodimer formed by a diatomic molecule A in an electronically excited state X (with total spin multiplicity S = 1/2) and a ground‑state O₂ molecule in its triplet (^3Σ_g^−) configuration. The excited state X of A possesses a static dipole polarizability tensor α (... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A planar polyatomic molecule \\(X\\) possesses a low‑frequency vibrational mode \\(\\nu_1\\) (fundamental frequency \\(\\omega_1 = 500\\ \\text{cm}^{-1}\\)) that is strongly coupled to a dissociative reaction coordinate leading to products \\(A + B\\). The molecule also has a s... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A photoactive heterocyclic compound exists in the ground electronic state as two rapidly interconverting conformers, **Syn** (S) and **Anti** (A), which are in thermal equilibrium with an experimentally measured equilibrium constant\n\nK_eq = [S]_g / [A]_g = 3.0.\n\nIn the **Sy... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a set of cylindrical mesoporous silica hosts with uniform, smooth pores of radius R and length L≫R. Water is confined inside these pores at temperature T=300 K and a fixed mass loading corresponding to an average water density ρ_conf = α ρ_bulk (with ρ_bulk=1.0 g cm⁻³ ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a binary mixture of a rod‑like cationic surfactant that forms cylindrical micelles and a flexible neutral polymer (e.g., polyethylenimine) at an air–water interface. The mixture self‑assembles into a macroscopic film whose internal structure can be approximated as a tw... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A closed‑shell ether molecule (M) is subjected to a mono‑energetic electron beam. Two competing pathways lead to the formation of an electronically excited methoxyl radical (CH₃O·*) that fluoresces in the UV (300–450 nm):\n\n1. **Forbidden pathway** – Direct electron impact pop... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A pressure‑swing adsorption (PSA) unit is to be designed for the removal of a trace contaminant A (molar fraction \\(y_A = 2000\\;\\text{ppm}_\\text{v}\\)) from a carrier gas B (nitrogen). The feed enters the adsorption column at \\(P_0 = 1\\;\\text{bar}\\) and \\(T_0 = 301\\;\... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a series of comb‑like polymers consisting of a rigid aromatic backbone bearing pendant allyl‑functionalized side chains. The side chains contain n repeat units of a flexible spacer, and are subsequently functionalized with benzimidazole groups via a thiol‑ene radical a... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A series of palladium(0) complexes bearing either monodentate phosphines (PPh₃, PEt₂Ph, PPh₂Et, PCy₃) or bidentate phosphines (dppe, dpph) are reacted with an aryl chloride whose aromatic ring is η⁶‑coordinated to a Cr(CO)₃ fragment (i.e., Ar–Cl·Cr(CO)₃). The following experime... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a library of \\(K\\) reference mass‑spectral signatures, each represented by a non‑negative \\(N\\)-dimensional column vector \\(\\mathbf{r}_k\\) \\((k=1,\\dots ,K)\\). An unknown mixture yields a measured spectrum \\(\\mathbf{y}\\in\\mathbb{R}^N_{\\ge 0}\\). The task ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A cryogenic separation plant produces liquid nitrogen (LN₂) that can be stored and later withdrawn to satisfy a known time‑varying demand d(t) over a planning horizon [0,T]. The plant dynamics are approximated by a low‑order linear time‑invariant (LTI) model derived from histor... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A municipal wastewater treatment plant operates an anaerobic digester that treats waste‑activated sludge (WAS) containing a mixture of polycyclic aromatic hydrocarbons (PAHs). To enhance PAH biodegradation, cellulose is added as a co‑substrate. Four continuous‑stirred‑tank reac... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider an isothermal catalytic reactor in which a single irreversible first‑order reaction \\n\\n\\[\\nA \\;\\xrightarrow{k}\\; B\\n\\] \\n\\ntakes place on a solid catalyst that deactivates rapidly. The intrinsic kinetic constant \\(k\\) (units s\\(^{-1}\\)) is known. Catal... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a monodisperse suspension of spherical gold nanoparticles of radius a (a \\ll 1 \\mu\\text{m}) in a mixed solvent. Each particle is capped with a thiol‑based ligand that endows the particle with a permanent dipole moment \\mathbf{p} whose direction is fixed relative to... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A family of quinone derivatives contains a quinone core bearing two hetero‑aryl substituents: one electron‑withdrawing pyridine ring and one electron‑donating pyrrole ring. In aqueous buffer (pH 7) the first reduction of each quinone is a reversible two‑electron process with a ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a cylindrical monolithic catalyst composed of two concentric porous wash‑coated layers on the wall of each channel.\n\n* Layer 1 (thickness \\(L_{1}\\)) contains a catalyst that promotes the selective reduction of nitrogen oxides (NO\\(_x\\)) by ammonia (NH\\(_3\\)) to... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A planar organic chromophore (point group C₂ᵥ) exhibits a photo‑generated triplet state (S = 1) whose zero‑field splitting (ZFS) tensor in its molecular frame (x′, y′, z′) is diagonal with principal values D = –0.020 cm⁻¹ and E = +0.001 cm⁻¹. The z′‑axis lies perpendicular to t... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A molecular scaffold consists of a rigid, planar hexasubstituted benzene core bearing N identical amphiphilic chromophoric side‑chains. Each side‑chain can engage in a pairwise directional hydrophobic/π‑stacking interaction with a complementary side‑chain on a neighboring scaff... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a flexible polymer chain adsorbing onto a planar solid surface from a dilute solution. The chain adopts an orientation distribution described by a probability density f(θ,t), where θ is the angle between a backbone segment and the surface normal, and t is time. Infrare... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a non‑linear polyatomic molecule that possesses two internal rotational (torsional) degrees of freedom described by the angular coordinates φ₁ and φ₂ (0 ≤ φᵢ < 2π). The kinetic energy operator for the coupled torsions is \n\n\\[\\hat{T}= -\\frac{\\hbar^{2}}{2}\\Bigl[ ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a solid‑state NMR study of an RNA aptamer that forms a tight complex with a small molecule ligand containing a single methyl group (CH₃). The sample is prepared for magic‑angle spinning (MAS) at a spinning frequency of 12 kHz and is subjected to continuous‑wave dynamic... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A soluble surfactant adsorbs at the air–water interface following the Frumkin adsorption isotherm \n\\[\\n\\Gamma = \\frac{\\Gamma_{\\max}\\,K\\,c\\,\\exp(-a\\Gamma)}{1+K\\,c\\,\\exp(-a\\Gamma)},\\n\\]\\nwhere \\( \\Gamma \\) is the surface excess, \\( \\Gamma_{\\max} \\) the ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A transparent conductive electrode is constructed as a two‑layer stack on a glass substrate:\n* **Layer A (thick ITO):**\n * Thickness \\(t_A = 150\\;\\text{nm}\\)\n * Complex refractive index at \\(\\lambda = 550\\;\\text{nm}\\): \\(\\tilde n_A = n_A + i k_A = 1.90 + i\\,0.0... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A set of three probe molecules is dissolved at infinite dilution in a single ionic liquid whose shear viscosity follows an Arrhenius temperature dependence\\n\\n\\[\\n\\eta(T)=\\eta_{0}\\,\\exp\\!\\left(\\frac{E}{RT}\\right),\\qquad \\eta_{0}=0.10\\;\\text{Pa·s},\\;E=5.0\\times... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider the gas‑phase radical‑radical reaction\n\n\\[\\mathrm{O}(^3\\!P) + \\mathrm{C_2H_5} \\;\\longrightarrow\\; \\mathrm{H}(^2\\!S) + \\mathrm{CH_3CHO}\\]\n\nHigh‑level CBS‑QB3 calculations locate the following stationary points on the doublet potential‑energy surface (rela... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a molecular system composed of \\(A\\) atoms. For each atom \\(A_i\\) we define a *redundant* atomic orbital (AO) set that contains \\(m\\) functions capable of spanning the occupied subspace (core + valence) and \\(n\\) functions that span the full AO basis (including... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A researcher is evaluating several computational protocols for predicting ¹³C NMR chemical shifts (δ) of organic molecules in the gas phase. For each molecule, the isotropic shielding constant σ is obtained with the GIAO method at a given level of theory, and the chemical shift... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "You are tasked with designing a comprehensive quasi‑relativistic density functional theory (DFT) investigation of a series of actinyl complexes of the form AnO₂ⁿ⁺ (An = U, Np, Pu; n = +2 for An(VI) and +1 for An(V)) coordinated by a neutral, six‑membered macrocycle that contain... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A traveling‑wave ion mobility spectrometer (TW‑IMS) operates with a neutral drift gas at temperature $T_0$ and pressure $P$. The traveling wave is defined by three controllable parameters: wave amplitude $V_{\\mathrm{w}}$ (peak voltage), wave velocity $u_{\\mathrm{w}}$ (speed o... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "An iron‑based alloy is being developed for use as a high‑temperature heat‑storage material in a rotary‑kiln biomass processor. The alloy contains 2 wt % Mn and 0.7 wt % C, and its surface is coated with an Al layer that forms an Al₂O₃ scale during high‑temperature exposure. The... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a binary liquid mixture of components 1 and 2. The molar masses are \\(M_{1}=150\\;\\text{g mol}^{-1}\\) and \\(M_{2}=32\\;\\text{g mol}^{-1}\\). The pure‑component densities \\(\\rho_{i}^{0}(T,p)\\) (in kg m\\(^{-3}\\)) are described by the simple linear equations\n\n... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A newly synthesized organic fluorophore (compound **X**) exhibits unusually strong fluorescence in the solid state, while its solution fluorescence is weak. Spectroscopic and computational investigations provide the following data:\n\n| Property | Monomer (solution) | Dimer (ag... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider an organic emitter that exhibits thermally activated delayed fluorescence (TADF) in solution. The excited‑state dynamics can be described by a kinetic scheme involving the lowest singlet (S₁) and triplet (T₁) states. The processes and their associated first‑order rate ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A carbonyl oxide (Criegee intermediate) of the general formula R₁R₂COO is generated in a supersonic jet expansion and interrogated by cavity‑enhanced Fourier‑transform microwave (FTMW) spectroscopy. For the specific case where R₁ = CH₃ and R₂ = C₂H₅, the molecule can adopt two ... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A macrocyclic ligand contains four nitrogen atoms that define a distorted trapezoidal core. The crystallographically determined Cartesian coordinates (in Å) of the nitrogen atoms are:\n- N₁: (0.000, 1.234, 0.015)\n- N₂: (2.456, -0.987, -0.012)\n- N₃: (4.912, 1.210, 0.008)\n- N₄... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A transition‑metal oxide nanocluster of the form \\([M_{x}O_{y}]^{n-}\\) (with a d⁰ metal center) exhibits several structural isomers that differ only in the arrangement of terminal oxo ligands. You are asked to investigate the electronic structure, stability, and spectroscopic... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "You are given a large collection of crystal structures of a single protein target (e.g., an enzyme) that exhibit subtle conformational variations. For each structure i (i = 1,\\dots ,N) you can perform molecular docking of a set of ligands j (j = 1,\\dots ,M) and obtain a docki... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A soluble [NiFe] hydrogenase from a Gram‑negative bacterium contains a catalytic nickel centre and a flavin mononucleotide (FMN) cofactor. Under anaerobic, NADH‑reducing conditions at pH 7.0 the enzyme can populate three distinct paramagnetic species that are observable by cont... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "Consider a diatomic molecule whose electronic ground state is a high‑spin ^6Σ+ state (spin quantum number S = 5/2). The molecule is studied in two vibrational levels, v = 0 and v = 1, of this electronic state. The rotational quantum number is N and the total angular momentum (e... | null |
Science (STEM) | Nemotron-Science-V1-RQA | null | [
{
"role": "user",
"content": "A single electromagnetic (EM) vector sensor is capable of measuring the complete electric‑field vector **E**(t) ∈ ℂ³ and magnetic‑field vector **H**(t) ∈ ℂ³ at a fixed observation point, thus providing a 6‑dimensional complex observation vector\n\n\\[\\mathbf{y}(t)=\\begin{bmat... | null |
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