Continuum interpretation of virial stress in molecular simulations

Arun K. Subramaniyan and C. T. Sun, accepted for publication in International Journal of Solids and Structures, doi:10.1016/j.ijsolstr.2008.03.016

The equivalence of the virial stress and Cauchy stress is reviewed
using both theoretical arguments and numerical simulations. Using
thermoelasticity problems as examples, we numerically demonstrate that
virial stress is equivalent to the continuum Cauchy stress. Neglecting
the velocity terms in the definition of virial stress as many authors
have recently suggested, can cause significant errors in interpreting
MD simulation results at elevated temperatures (T > 0 K).