Advanced Examples#
These examples are for users who want to extend the nvalchemi-toolkit framework. They require understanding of the intermediate tier.
01 — Biased Potential: BiasedPotentialHook for harmonic COM restraints and umbrella sampling patterns.
02 — Custom Hook: Implementing the Hook protocol with a full radial distribution function accumulator.
03 — Custom Convergence: ConvergenceHook with multiple criteria and custom_op for arbitrary convergence logic.
04 — MACE NVT: Using a real MACE MLIP for NVT dynamics; automatic neighbor list wiring via ModelConfig; LJ fallback for CI.
05 — Custom Integrator: Subclassing BaseDynamics to implement a velocity-rescaling thermostat; the pre_update/post_update contract; _init_state for stateful integrators.
07 — Composable Model Composition: Combining LJ + Ewald models with
the + operator; PipelineModelWrapper for dependent pipelines.
08 — AIMNet2 + Ewald Pipeline: Composing AIMNet2 with Ewald electrostatics and DFTD3 dispersion in a multi-group pipeline.
09 — UMA NVE/NVT: Driving the fairchem UMA foundation model through
NVE / NVT dynamics with energy-drift tracking; OMat crystals and OMol
molecules via task selection on UMAWrapper.from_checkpoint.
10 — MACE Training: Training a ScaleShiftMACE model with the ALCHEMI training stack; Zarr dataloading, scheduled Huber losses, EMA, checkpointing, validation, and distributed launch patterns.
Writing a Custom Hook: Radial Distribution Function
Building a Custom Integrator by Subclassing BaseDynamics
UMA Foundation Model: NVE / NVT / NPT Molecular Dynamics
