Lennard-Jones potential as a metatomic energy model

This repository contains an implementation of the classic Lennard-Jones potential as a metatomic model.

This is intended to be used when testing the integration of metatomic models with various simulation engines; but can also serve as a relatively complete example of how to write your own models and use neighbor lists.

Installation

pip install git+https://github.com/metatensor/lj-test

# if you are working on Linux or Windows and DO NOT have a CUDA GPU
pip install --extra-index-url=https://download.pytorch.org/whl/cpu git+https://github.com/metatensor/lj-test

API

import metatomic_lj_test

# `with_extension` controls wether the model uses custom
# TorchScript operators defined in a C++ extension library
# or a pure PyTorch implementation
model = metatomic_lj_test.lennard_jones_model(
    atomic_type=12,
    cutoff=3.4,
    sigma=1.5,
    epsilon=23.0,
    length_unit="Angstrom",
    energy_unit="eV",
    with_extension=False,
)

model.save("lennard-jones.pt", collect_extensions="extensions/")