Overview

MDStressLab++ is a KIM-compliant program for postprocessing molecular dynamics (MD) or molecular statics (MS) simulations to compute atomistic stress fields using different definitions of the atomistic stress tensor.

For more information on KIM (Knowledgebase of Interatomic Models), see openkim.org.

MDStressLab++ provides the following capabilities:

Compute the Cauchy and first Piola-Kirchhoff versions of the Hardy and virial stress tensors on a user-defined grid. See [AdmalTadmor2010], [AdmalTadmor2011], [AdmalTadmor2016a].
Integrated Python tools for visualizing stress fields. See Visualization Utilities.

Key Features

LAMMPS compatibility: Atomistic configurations can be read from LAMMPS-style dump files.
No process_dedr required: Atomistic stress can be computed even for interatomic potentials that do not provide interatomic forces derived from the derivatives of energy with respect to distances.
Flexible weight functions via CRTP: User-defined weighting functions can be implemented easily by inheriting from the Method template class using the Curiously Recurring Template Pattern (CRTP).
Lattice-dependent averaging domains: Reduced noise is achieved by using lattice-dependent averaging domains. See [AdmalTadmorShi2019].
Library or script mode: MDStressLab++ can be used as a C++ library within custom applications or driven by user-defined input scripts for standard workflows.

Installation instructions

Authors

This code was written by:

Prof. Nikhil Chandra Admal (UIUC)
Min Shi (University of Minnesota)
Prof. Ellad B. Tadmor (University of Minnesota)

and is based on their collaborative research.

How to Cite MDStressLab++

When publishing results obtained using this program, please acknowledge that the code was obtained from https://github.com/nikhil-admal/mdstresslab and cite the following publications:

N. C. Admal and E. B. Tadmor,
A unified interpretation of stress in molecular systems,
Journal of Elasticity, 100, 63–143 (2010).
N. C. Admal and E. B. Tadmor,
Stress and heat flux for arbitrary multi-body potentials: A unified framework,
Journal of Chemical Physics, 134, 184106 (2011).
N. C. Admal and E. B. Tadmor,
Material fields in atomistics as pull-backs of spatial distributions,
Journal of the Mechanics and Physics of Solids, 89, 59–76 (2016).
N. C. Admal and E. B. Tadmor,
The non-uniqueness of the atomistic stress tensor and its relationship to the generalized Beltrami representation,
Journal of the Mechanics and Physics of Solids, 93, 72–92 (2016).
N. C. Admal, E. B. Tadmor, and M. Shi, Noise filtering in atomistic stress calculations for crystalline materials, *Journal of the Mechanics and Physics of Solids, 144, 104083 (2020).