HSMA: An O(N) electrostatics package implemented in LAMMPS

TL;DR

The paper introduces HSMA, an O(N) electrostatics solver integrated into LAMMPS, offering faster and accurate Coulomb interaction calculations for 2D and 3D periodic systems with dielectric effects.

Contribution

It implements two fast Coulomb solvers, HSMA3D and HSMA2D, into LAMMPS with hybrid parallelization and vectorization, outperforming traditional methods like PPPM in speed.

Findings

HSMA achieves O(N) computational complexity.

The implementation is highly parallelized and vectorized.

HSMA outperforms PPPM in speed across various particle numbers.

Abstract

We implement two recently developed fast Coulomb solvers, HSMA3D [J. Chem. Phys. 149 (8) (2018) 084111] and HSMA2D [J. Chem. Phys. 152 (13) (2020) 134109], into a new user package HSMA for molecular dynamics simulation engine LAMMPS. The HSMA package is designed for efficient and accurate modeling of electrostatic interactions in 3D and 2D periodic systems with dielectric effects at the O(N) cost. The implementation is hybrid MPI and OpenMP parallelized and compatible with existing LAMMPS functionalities. The vectorization technique following AVX512 instructions is adopted for acceleration. To establish the validity of our implementation, we have presented extensive comparisons to the widely used particle-particle particle-mesh (PPPM) algorithm in LAMMPS and other dielectric solvers. With the proper choice of algorithm parameters and parallelization setup, the package enables calculations of electrostatic interactions that outperform the standard PPPM in speed for a wide range of particle numbers.