LAMMPS Patch Release 2 June 2020

LAMMPS Patch Release Overview

What is LAMMPS primarily used for?

LAMMPS has potentials for solid-state materials (metals, semiconductors) and soft matter (biomolecules, polymers) and coarse-grained or mesoscopic systems. It can be used to model atoms or, more generically, as a parallel particle simulator at the atomic, meso, or continuum scale.

LAMMPS runs on single processors or in parallel using message-passing techniques and a spatial-decomposition of the simulation domain. Many of its models have versions that provide accelerated performance on CPUs, GPUs, and Intel Xeon Phis. The code is designed to be easy to modify or extend with new functionality.

Changes since the patch release 5 May 2020:

• Support for building neighbor lists on the GPU with triclinic boxes in the GPU package (Trung Nguyen, Northwestern U) PR #2073
• Major refactoring of AtomVec classes in order to simplify adding such classes in the future. (Steve Plimpton, Stan Moore, SNL) PR #1788 , PR #2080, PR #2092
• Add new thread-safe and simpler to use tokenizer and word counter classes. Apply to file readers for manybody potentials and several other places. Richard Berger (Temple U) PR #2113
• Integrate {fmt} to generate printf() style formatted C++ strings and thus make generating those less complex and safer. Also add utils::logmesg() convenience function to send string to both, screen and logfile, with one call. Axel Kohlmeyer (Temple U), PR #2103
• Add the first step of a comprehensive integrated unittest library with support for testing a selection of pair, bond, and angle styles under various conditions and with multiple uses. (Axel Kohlmeyer and Richard Berger, Temple U) PR #2098 , PR #2100, PR #2101, PR #2108 , PR #2114, PR #2119
• Add support for molecule fragments to fix bond/react (Jake Gissinger, CU Bolder), PR #2106
• Partial cleanup of makefiles for conventional build (Mike Brown, Intel Corp), PR #2071
• Update of Kokkos library to version 3.1.1 (Christoph Junghans, LANL and the Kokkos developers) PR #2070
• Update default version of LATTE to 1.2.2 (Christoph Junghans, LANL) PR #2069
• More tweaks and updates to CMake scripts (Christoph Junghans, LANL), PR #2068, PR #2069
• Various small updates and corrections (various authors) PR #2074, PR #2077, PR #2080, PR #2082, PR #2091, PR #2093, PR #2094, PR #2095, PR #2105, PR #2110, PR #2111, PR #2116, PR #2118

Backward compatibility notices:

• The refactoring of the AtomVec classes will likely break any external packages that provide their own AtomVec classes or contain styles that depend on the name of per-atom properties that were renamed. All AtomVec derived classes bundled within LAMMPS have been updated.
• The refactored reading and parsing of potential files will now be reporting an error on Fortran-style double precision floating-point numbers with a “d” exponent instead of silently ignoring the “d” and the exponent. Potential files bundled with LAMMPS have been corrected (their exponent was “d0”, so it does – by chance – not affect any results).
• The (unsupported) previous library of simple run tests for LAMMPS has been replaced by a more systematic and comprehensive unit test library which will be significantly expanded over time.

This release has 2 assets:

• Source code (zip)
• Source code (tar.gz)

Visit the release page to download them.

About LAMMPS

LAMMPS (Large-scale Atomic/Molecular Massiveley Parallel Simulator) is an open-source molecular dynamics simulator written in C++ from Sandia National Laboratories, and is designed for parallel machines. LAMMPS models an ensemble of particles in a liquid, solid or gaseous state. It can model atomic polymeric, biological, metallic, or mesoscale systems using a variety of force fields and boundary conditions and is easily extensible.