Models and licences¶

Labels¶

fm.load, fm.md, fm.calc and the CLI take a model as a label, a local path or a URL. List the labels with:

fastmace models

Label	Head	Licence	Kind
`mp0-medium`, `mp0-large`, `mp0b3-medium`, `mpa0-medium`		MIT	MACE-MP foundation models (PBE)
`omat0-medium`, `matpes-pbe`, `matpes-r2scan`		ASL	OMAT and MatPES models
`mh1-omat`, `mh1-mp`, `mh1-r2scan`	fixed by the label	ASL	MACE-MH-1 with one head
`mh1`	`head=` required	ASL	MACE-MH-1, any of its six heads
`polar1-s`, `polar1-m`, `polar1-l`		ASL	MACE-POLAR-1 (needs `[polar]`)
`omol0-xl` (`omol0`)	`omol`	ASL	MACE-OMOL-0, molecules; takes `charge=` and `spin_multiplicity=`
`off23-small`, `off23-medium`, `off23-large`, `off23b-medium`, `off24-medium`		ASL	MACE-OFF, organic molecules and crystals

fastmace models prints the file names and SHA-256 of each checkpoint.

Heads¶

A multi-head checkpoint without head= raises ValueError listing its heads. There is no default head. MH-1's heads are matpes_r2scan, mp_pbe_refit_add, spice_wB97M, oc20_usemppbe, omol and omat_pbe.

Where checkpoints come from¶

fm.load(label) looks for the file in $FASTMACE_MODELS, then in <cache root>/models. With download=True it fetches the file from its official URL and checks the SHA-256 before keeping it. FastMACE never ships or redistributes model weights.

A file outside the label table needs sha256= (its expected hash) or trusted=True, because loading a checkpoint runs pickled code.

Licences¶

The weights' licence binds you independently of FastMACE's MIT licence. Several foundation models, MACE-MH-1 among them, are under the Academic Software License (ASL, non-commercial use only). FastMACE shows each model's licence once per process as a ModelLicenceWarning, and the run report has a licence: line read from the label table.

FastMACE's own licence and its dependencies' licences are on the Licences page.

Which model for what¶

Inorganic crystals: MH-1 (mh1-r2scan or mh1 with a head), OMAT-0 or MP-0. MH-1 runs at its fastest in FastMACE through the MH-1 rewrites.
Long-range electrostatics: MACE-POLAR-1. POLAR-1-S showed a Fukui charge runaway on NaNbO3, and all POLAR sizes failed on NaTaO3 in our tests.
Molecules: OMOL-0 (charge and spin) or MACE-OFF (organic elements only: H, C, N, O, F, P, S, Cl, Br, I).
Dispersion: see NPT and D3. MACE-OFF, OMOL-0 and MH-1's omol head already contain dispersion, so dispersion="d3bj" is refused for them.