Graham's law of effusion in dense systems with nonuniform interactions

Abstract

We investigate Graham's law of effusion in a series of molecular dynamics simulations. We show that the law remains valid not only in a dilute gas, but also in fluids dense enough to cause localization, even when various particles of the system interact according to varying interatomic force laws. Although Maxwellian velocity distribution is a sufficient condition for Graham's law of effusion to hold, it is not strictly necessary, in the sense that the law is obeyed even by systems that deviate significantly from Maxwellian. PACS Nos.: 05.20.Dd, 51.10.+y