| name | thermal-properties |
| description | Thermal Properties (13 sub-skills: anharmonicity, bond-distribution, free-energy-calculation, gruneisen-qha, md-trajectory-tools, molecular-dynamics, msd-diffusion, phonon, phonon-from-outcar, quasi-harmonic-debye, rdf-analysis, thermal-conductivity, vacf-vdos) |
Thermal Properties
Phonon calculations, molecular dynamics, free energy calculations, and quasi-harmonic thermodynamics for crystalline and amorphous materials.
Sub-Skills
| Sub-Skill | Directory | Description |
|---|
| Phonon Calculations | phonon/ | Harmonic phonon band structure, DOS, and thermodynamic properties via finite displacements (ASE+MACE+phonopy) or DFPT (QE ph.x) |
| Molecular Dynamics | molecular-dynamics/ | NVE/NVT/NPT MD simulations with ASE+MACE or LAMMPS; trajectory analysis (RDF, MSD, diffusion) |
| Free Energy Calculation | free-energy-calculation/ | Helmholtz/Gibbs free energy via thermodynamic integration (Frenkel-Ladd for solids, UF model for liquids, reversible scaling for F(T)), phase stability and melting points |
| Gruneisen and QHA | gruneisen-qha/ | Mode Gruneisen parameters, quasi-harmonic approximation for thermal expansion and T-dependent bulk modulus |
| Quasi-Harmonic Debye Model | quasi-harmonic-debye/ | Debye model thermodynamics from E(V) data: Debye temperature, heat capacity, thermal expansion, Gruneisen parameter without phonon calculations |
| Anharmonicity Score | anharmonicity/ | Quantify anharmonicity (sigma^A) via one-shot thermal displacement; decide if QHA is valid or MD is needed |
Method Decision Guide
What thermal property do you need?
Phonon band structure / DOS / Cv / entropy / free energy (harmonic)?
--> phonon/ (finite displacement or DFPT)
Helmholtz/Gibbs free energy (full anharmonic) / melting point / phase stability?
--> free-energy-calculation/ (thermodynamic integration via LAMMPS)
Diffusion coefficient / melting / phase transition / liquid properties?
--> molecular-dynamics/ (MD simulation)
Thermal expansion / T-dependent bulk modulus / Gruneisen parameters?
--> gruneisen-qha/ (QHA with phonons at multiple volumes)
Quick Debye temperature / heat capacity estimate without phonon calculations?
--> quasi-harmonic-debye/ (Debye model from E(V) curve only)
Is my material too anharmonic for QHA? Need sigma^A score?
--> anharmonicity/ (one-shot thermal displacement test)
sigma^A < 0.2 --> QHA is safe
sigma^A 0.2-0.5 --> QHA is marginal, validate with MD
sigma^A > 0.5 --> Use MD instead of QHA
Quick screening vs. publication accuracy?
Quick --> ASE + MACE (all sub-skills support this)
Publication --> QE DFT (phonon/, gruneisen-qha/) or LAMMPS with validated potential (molecular-dynamics/, free-energy-calculation/)
