title: Communication: thermodynamics of condensed matter with strong pressure-energy correlations.
abstract: We show that for any liquid or solid with strong correlation between its NVT virial and potential-energy equilibrium fluctuations, the temperature is a product of a function of excess entropy per particle and a function of density, T = f(s)h(ρ). This implies that (1) the system's isomorphs (curves in the phase diagram of invariant structure and dynamics) are described by h(ρ)/T = Const., (2) the density-scaling exponent is a function of density only, and (3) a Grüneisen-type equation of state applies for the configurational degrees of freedom. For strongly correlating atomic systems one has h(ρ) = ∑(n)C(n)ρ(n/3) in which the only non-zero terms are those appearing in the pair potential expanded as ν(r) = ∑(n)ν(n)r(-n). Molecular dynamics simulations of Lennard-Jones type systems confirm the theory.
authors.affiliation: DNRF Centre Glass and Time, IMFUFA, Department of Sciences, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark.
authors.forename: Trond S
authors.initials: TS
authors.lastname: Ingebrigtsen
authors.forename: Lasse
authors.initials: L
authors.lastname: Bøhling
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Schrøder
authors.forename: Jeppe C
authors.initials: JC
authors.lastname: Dyre