BOPfox program for tight-binding and analytic bond-order potential calculations

TL;DR

This paper presents the efficient implementation of analytic bond-order potentials in the BOPfox program, enabling detailed interatomic interaction modeling with scalable and parallelizable calculations for magnetic and non-magnetic systems.

Contribution

It introduces a comprehensive implementation of analytic BOPs in BOPfox, including magnetic models, force calculations, and parallelization strategies, advancing computational materials modeling.

Findings

Demonstrates scalable performance with increasing atom numbers

Provides methods for calculating forces, stresses, and magnetic torques

Outlines options for speeding up and parallelizing BOP calculations

Abstract

Bond-order potentials (BOPs) provide a local and physically transparent description of the interatomic interaction. Here we describe the efficient implementation of analytic BOPs in the BOPfox program and library. We discuss the integration of the underlying non-magnetic, collinear-magnetic and noncollinear-magnetic tight-binding models that are evaluated by the analytic BOPs. We summarize the flow of an analytic BOP calculation including the determination of self-returning paths for computing the moments, the self-consistency cycle, the estimation of the band-width from the recursion coefficients, and the termination of the BOP expansion. We discuss the implementation of the calculations of forces, stresses and magnetic torques with analytic BOPs. We show the scaling of analytic BOP calculations with the number of atoms and moments, present options for speeding up the calculations and outline different concepts of parallelisation. In the appendix we compile the implemented equations of the analytic BOP methodology and comments on the implementation. This description should be relevant for other implementations and further developments of analytic bond-order potentials.