Breakdown of excess entropy scaling for systems with thermodynamic anomalies.
This paper presents a simulation study of the applicability of the Rosenfeld entropy scaling to the systems which cannot be approximated by the effective hard spheres. Three systems are studied: the Herzian spheres, the Gauss core model, and a soft repulsive shoulder potential. These systems demonstrate diffusion anomalies at low temperatures: the diffusion coefficient increases with increasing density or pressure. It is shown that for the first two systems belonging to a class of bounded potentials, the Rosenfeld scaling formula is valid only in the infinite-temperature limit where there are no anomalies. For the soft repulsive shoulder potential, the scaling formula is valid already at sufficiently low temperatures, however, out of the anomaly range.
Fomin
Yu D
YD
Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk 142190, Moscow Region, Russia.
Ryzhov
V N
VN
Gribova
N V
NV