Phase coexistence of cluster crystals: Beyond the gibbs phase rule

Journal Article

We report a study of the phase behavior of multiple-occupancy crystals through simulation. We argue that in order to reproduce the equilibrium behavior of such crystals, it is essential to treat the number of lattice sites as a constraining thermodynamic variable. The resulting free-energy calculations thus differ considerably from schemes used for single-occupancy lattices. Using our approach, we obtain the phase diagram and the bulk modulus for a generalized exponential model that forms cluster crystals at high densities. We compare the simulation results with existing theoretical predictions. We also identify two types of density fluctuations that can lead to two sound modes and evaluate the corresponding elastic constants. © 2007 The American Physical Society.

Full Text

Duke Authors

Cited Authors

  • Mladek, BM; Charbonneau, P; Frenkel, D

Published Date

  • 2007

Published In

Volume / Issue

  • 99 / 23

PubMed ID

  • 18233385

International Standard Serial Number (ISSN)

  • 0031-9007

Digital Object Identifier (DOI)

  • 10.1103/PhysRevLett.99.235702