The MOLDY short-range molecular dynamics package

TL;DR

The paper introduces a parallelized Fortran-based molecular dynamics package, MOLDY, optimized for short-range potentials and embedded atom method systems, with enhanced performance on multicore systems and applications to metals and alloys.

Contribution

It presents a new parallelized version of MOLDY with modular potentials, optimized for shared memory systems, and demonstrates its effectiveness on realistic metal and alloy simulations.

Findings

Efficient parallel performance on multicore processors.

Versatile in handling various boundary conditions and ensembles.

Successfully applied to simulate copper compression and iron-carbon alloy migration.

Abstract

We describe a parallelised version of the MOLDY molecular dynamics program. This Fortran code is aimed at systems which may be described by short-range potentials and specifically those which may be addressed with the embedded atom method. This includes a wide range of transition metals and alloys. MOLDY provides a range of options in terms of the molecular dynamics ensemble used and the boundary conditions which may be applied. A number of standard potentials are provided, and the modular structure of the code allows new potentials to be added easily. The code is parallelised using OpenMP and can therefore be run on shared memory systems, including modern multicore processors. Particular attention is paid to the updates required in the main force loop, where synchronisation is often required in OpenMP implementations of molecular dynamics. We examine the performance of the parallel code in detail and give some examples of applications to realistic problems, including the dynamic compression of copper and carbon migration in an iron-carbon alloy.