Liquid–vapor coexistence of vibrating polygonal and polyhedral molecules composed of hard spheres interacting with square well potentials

Abstract

Liquid–vapor coexistence is calculated via molecular dynamics for a variety of polygonal shaped molecules and for the platonic polyhedra. Tangential hard spheres interacting with an attractive square-well potential form the molecules. Spheres within the molecules are bonded together with in a small size infinitely high square-wells to keep them vibrating at the appropriate intra molecular distance. The total density of the system is near to its critical value. Liquid–vapor coexistence is obtained with the process of spinodal decomposition. Orthobaric densities, surface tensions, vapor pressures and Interfacial widths are calculated along with critical temperatures and densities. These polygonal and polyhedral shapes can be used in the development of a theoretical equation of state.