A localized momentum constraint for non-equilibrium molecular dynamics simulations.

The article presents an overview of localized momentum constraint for non-equilibrium molecular dynamics simulations, which is used to control momentum evolution in sub-regions in molecular dynamics simulations, is derived from Gauss’s principle of least constraint and is based on the physics equations of Irving and Kirkwood. A discussion of the practical uses of the constraint, which can can prescribe arbitrary flow fields in non-equilibrium molecular dynamics simulations and can form a mathematical framework for introducing coupling constraints at the boundary between continuum and discrete systems in the field of physics, is presented.