chem-thermochemistry

Compute gas-phase thermodynamic quantities and reaction free energies using MLIP-driven vibrations and ASE IdealGasThermo.

144|21|Updated Jan 8, 2026

Search Tags:#thermochemistry #mlip #gas-phase #gibbs free energy #vibrational frequencies #ideal-gas thermo #reaction energetics

Ready to run

npx skills add https://github.com/learningmatter-mit/AtomisticSkills --skill chem-thermochemistry

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: chem-thermochemistry
Source: https://github.com/learningmatter-mit/AtomisticSkills/tree/main/.agents/skills/chem-thermochemistry
Command: npx skills add https://github.com/learningmatter-mit/AtomisticSkills --skill chem-thermochemistry

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires ase, numpy, scipy, and includes scripts (resource) and references (resource) components.

What problem does it solve?

Accurately estimate gas-phase thermodynamic properties and reaction free energies without running expensive DFT thermochemistry.

Core Features & Use Cases

Gas-phase thermodynamics (IGRRHO): Computes enthalpy H(T), entropy S(T,P), and Gibbs free energy G(T,P) for isolated molecules/species using ASE’s IdealGasThermo with ideal-gas/rigid-rotor/harmonic-oscillator assumptions.
MLIP-powered vibrational analysis: Relaxes structures and derives vibrational frequencies via finite-difference vibrational Hessians driven by an MLIP calculator.
Reaction thermochemistry: Parses balanced reactions and aggregates per-species contributions to produce ΔH, ΔS, and ΔG.
Use case: Evaluate temperature- and pressure-dependent feasibility of gas-phase reaction pathways (e.g., combustion or synthesis routes) using a consistent MLIP + harmonic thermochemistry workflow.

Quick Start

Ask the skill to compute reaction thermochemistry for “2H2 + O2 -> 2H2O” at 298.15 K and 101325 Pa using the MACE-OMAT-0-small model, saving the results to an output directory of your choice.

Frequently Asked Questions about chem-thermochemistry

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I calculate gas-phase thermochemistry from MLIP forces without running DFT?▼

You can calculate gas-phase thermochemistry by relaxing structures and computing finite-difference vibrational frequencies from MLIP forces, then passing them to ASE IdealGasThermo to derive enthalpy, entropy, and Gibbs free energy.

Can I evaluate reaction free energies for combustion pathways using MLIP and ASE?▼

Yes, you can evaluate reaction free energies by parsing balanced reactions and aggregating per-species thermodynamic contributions computed via MLIP-driven vibrational analysis and ASE IdealGasThermo to produce reaction enthalpy, entropy, and Gibbs free energy.

What is the ideal-gas rigid-rotor harmonic-oscillator approximation for computing molecular Gibbs free energy?▼

The ideal-gas rigid-rotor harmonic-oscillator approximation is a method to estimate gas-phase thermodynamic properties by treating molecules as rigid rotors with harmonic vibrations, yielding enthalpy H(T), entropy S(T,P), and Gibbs free energy G(T,P) without DFT.

Do I need ASE and an MLIP wrapper to compute vibrational frequencies for thermochemistry?▼

Yes, you need an available MLIP wrapper to provide forces and ASE for thermochemistry and ideal-gas rigid-rotor harmonic-oscillator modeling to perform geometry relaxation and finite-difference vibrational frequency calculations.

Can I compute temperature- and pressure-dependent reaction thermochemistry for gas-phase synthesis routes?▼

Yes, you can compute temperature- and pressure-dependent reaction thermochemistry by specifying conditions like 298.15 K and 101325 Pa, allowing the workflow to evaluate the feasibility of gas-phase synthesis routes using a consistent MLIP and harmonic thermochemistry approach.

What are the limitations of using MLIP-driven vibrational analysis for reaction thermochemistry?▼

This MLIP-driven vibrational analysis is limited to gas-phase thermodynamic estimation under the ideal-gas/rigid-rotor/harmonic-oscillator approximation, applying only to single-species estimation and balanced gas-phase reaction free energy evaluation across specified conditions.