LAMMPS

LAMMPS is a production-grade molecular dynamics engine. The NequIP framework provides two different integrations for LAMMPS.

pair_nequip_allegro

The pair_nequip_allegro page provides details on using the LAMMPS plugins hosted in the pair_nequip_allegro repository provides pair styles to use NequIP framework interatomic potentials directly in LAMMPS. This repository contains:

• pair_nequip for the NequIP message-passing GNN model

• pair_allegro for the strictly local Allegro model

ML-IAP

LAMMPS ML-IAP is a separate LAMMPS integration that provides a different interface for using machine learning potentials. The NequIP framework provides a wrapper and workflow tools for ML-IAP.

See ML-IAP for detailed instructions.

Summary

The following table summarizes key differences between the integration approaches:

Feature	pair_nequip_allegro	ML-IAP
LAMMPS Compilation	See pair_nequip_allegro repo	See “Building ML-IAP”
Multirank Support	pair_nequip: Single rank only pair_allegro: Multirank	Multirank
Model Preparation	nequip-compile	nequip-prepare-lmp-mliap
Acceleration Modifiers	pair_nequip: None pair_allegro: enable_TritonContracter	NequIP: enable_OpenEquivariance Allegro: enable_CuEquivarianceContracter, enable_TritonContracter

• pair_nequip_allegro
• ML-IAP