Families of intermolecular potentials corresponding to identical structures of noncrystalline substances in the method of molecular dynamics

摘要

An analysis of the Born-Green-Bogolyubov equation of the theory of liquids shows that there exists a family of interparticle potentials capable of generating the same required structure of a noncrystalline (liquid or amorphous) system at T > 0 by the method of molecular dynamics. (The potentials of this family are linear combinations of some potential generating this structure at temperature T and the potential generating the same structure at absolute zero.) This theorem was checked for two examples, namely, a one-component system with 3998 particles in the main cube with periodic boundary conditions and a purely repulsive potential u(r) similar to r(-4) and a two-component system of the same size with Lennard-Jones interparticle pair potentials. If pair correlation functions coincide, three-particle (ternary) correlation functions of the system also coincide or are fairly close to each other. A similar family of potentials can be constructed from potentials that generate identical structures at two different positive temperatures. This conclusion was checked for liquid gallium and Cu2Te telluride.