title: Virial coefficients and equation of state of the penetrable sphere model.
abstract: We study the penetrable sphere (alias square mound) model in the fluid phase by means of the virial expansion, molecular dynamics simulations, and Ornstein-Zernike integral equation. The virial coefficients up to B(8) are expressed as polynomials in the Boltzmann factor with the coefficients calculated by a Monte Carlo integration. New data for pressure and internal energy are obtained by molecular dynamics simulations with attention paid to finite-size errors and properties of the Andersen thermostat. The data and virial coefficients are correlated by a formula for the Helmholtz free energy. We also propose a new closure for the Ornstein-Zernike equation and test several other closures.
authors.affiliation: Department of Physical Chemistry, Institute of Chemical Technology, Prague, 166 28 Praha 6, Czech Republic.
authors.forename: Linda
authors.initials: L
authors.lastname: Viererblová
authors.forename: Jirí
authors.initials: J
authors.lastname: Kolafa
authors.forename: Stanislav
authors.initials: S
authors.lastname: Labík
authors.forename: Anatol
authors.initials: A
authors.lastname: Malijevský