Liquid Polymorphism and Density Anomaly in a Lattice Gas Model
Statistical Mechanics
2009-11-10 v1 Other Condensed Matter
Abstract
We present a simple model for an associating liquid in which polymorphism and density anomaly are connected. Our model combines a two dimensional lattice gas with particles interacting through a soft core potential and orientational degrees of freedom represented through thermal \char`\"{}ice variables\char`\"{} . The competition between the directional attractive forces and the soft core potential leads to a phase diagram in which two liquid phases and a density anomaly are present. The coexistence line between the low density liquid and the high density liquid has a positive slope contradicting the surmise that the presence of a density anomaly implies that the high density liquid is more entropic than the low density liquid.
Cite
@article{arxiv.cond-mat/0407763,
title = {Liquid Polymorphism and Density Anomaly in a Lattice Gas Model},
author = {Vera B. Henriques and Marcia C Barbosa},
journal= {arXiv preprint arXiv:cond-mat/0407763},
year = {2009}
}