Elemental Energies
Goal
To provide a centralized library of the most stable phases (ground states) for each element and their corresponding reference energies calculated using different Machine Learning Interatomic Potentials (MLIPs). This avoids redundant relaxations and ensure consistency in thermodynamics calculations (e.g., formation energy, stability).
Instructions
1. Retrieve Elemental Energies
To get the energies for a list of elements from a specific checkpoint:
# Env: base-agent
python .agents/skills/mat-elemental-energies/scripts/get_elemental_energies.py --elements Li Fe O --checkpoint mace-mp-medium
Library Status
As of 2026-01-30, the library is fully expanded and contains 89 elements (Ground states from H to Lr) across 36 MLIP variants, including:
- MACE: MACE-MP (S/M/L), MACE-MH-0/1 (all heads), MACE-OMAT (S/M), MACE-MATPES (PBE/R2SCAN).
- MatGL: CHGNet (MPtrj, MatPES), M3GNet (MP, MatPES), TensorNet (MatPES).
- FairChem: UMA (S/M) with all heads (omat, omol, oc20).
Constraints
- Materials Project: Structures must be queried from Materials Project to ensure they represent the true ground-state phases.
- Naming: Library files must follow the
<checkpoint_name>_energies.jsonformat. - Units: Energies are stored as eV/atom (total potential energy of the relaxed structure divided by the number of atoms).
- Relaxation: The stored value comes from relaxing both cell and coordinates
(
relax_cell=True). A positions-only relaxation leaves the reference above the potential's own minimum and biases every formation energy that uses it. - Molecular-crystal elements are sensitive: for O, N, F, Cl, H the MP ground state
is a van der Waals-bound molecular crystal whose MLIP-relaxed cell differs a lot from
the DFT cell, so the cell relaxation matters more here than for metals. With
TensorNet-PES-MatPES-PBE-2025.2, mp-12957 (O2) gives -5.118 eV/atom fully relaxed versus -4.968 positions-only. More than one MP entry can also tie atenergy_above_hull = 0for these elements (O2: mp-12957 and mp-1524462), so pin thematerial_idrather than relying on a formula lookup returning a stable order.
Author: Bowen Deng Contact: GitHub @learningmatter-mit