metatrain is a command line interface (CLI) to train and evaluate atomistic models of various architectures. It features a common yaml option inputs to configure training and evaluation. Trained models are exported as standalone files that can be used directly in various molecular dynamics (MD) engines (e.g. LAMMPS, i-PI, ASE …) using the metatensor atomistic interface.

The idea behind metatrain is to have a general hub that provides a homogeneous environment and user interface, transforming every ML architecture into an end-to-end model that can be connected to an MD engine. Any custom architecture compatible with TorchScript can be integrated into metatrain, gaining automatic access to a training and evaluation interface, as well as compatibility with various MD engines.

Note: metatrain does not provide mathematical functionalities per se, but relies on external models that implement the various architectures.

List of Implemented Architectures

Currently metatrain supports the following architectures for building an atomistic model:

Name	Description
GAP	Sparse Gaussian Approximation Potential (GAP) using Smooth Overlap of Atomic Positions (SOAP).
PET	Point Edge Transformer (PET), interatomic machine learning potential
NanoPET (experimental)	Re-implementation of the original PET with slightly improved training and evaluation speed
PET (deprecated)	Original implementation of the PET model used for prototyping, now deprecated in favor of the native metatrain PET implementation.
SOAP BPNN	A Behler-Parrinello neural network with SOAP features