MDStressLab - Computing stress in atomistic simulations

Nikhil Chandra Admal
Postdoctoral Research Scholar
Materials Science and Engineering
University of California Los Angeles

Co-authors: Min Shi, Ellad Tadmor

In this talk, we present the capabilities of MDStressLab, a post-processing tool for LAMMPS simulations to compute stress fields using different definitions of the atomistic stress. Currently, MDStressLab can be used to compute Cauchy and Piola--Kirchhoff versions of the Hardy, Tsai and virial stress tensors. An additional feature to decompose the atomistic stress into irrotational and solenoidal parts will be presented. This decomposition is performed at the discrete level on the interatomic forces as opposed to the decomposition of the continuum field. The origin of this decomposition and its implications in visualization parallels the role of Helmholtz--Hodge decomposition for fluids. Finally, we present recent additions to MDStressLab concerning the reduction of noise in stress calculations.