A D Bruce | PubMed Health

PubMed2002

Lattice-switch Monte Carlo method: application to soft potentials.

The lattice-switch Monte Carlo method, recently introduced and applied in the context of hard spheres, is extended to particles interacting through a soft potential. The method utilizes a transformation that switches between configurations of two different crystalline structures, allowing the phase space of both structures to be explored in a single simulation and the difference between their free energies to be determined directly. We apply the method to determine the fcc-hcp crystalline phase behavior of the classical Lennard-Jones solid.

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PubMed1999

Critical-point finite-size scaling in the microcanonical ensemble.

We develop a scaling theory for the finite-size critical behavior of the microcanonical entropy (density of states) of a system with a critically divergent heat capacity. The link between the microcanonical entropy and the canonical energy distribution is exploited to establish the former, and corroborate its predicted scaling form, in the case of the 3d Ising universality class. We show that the scaling behavior emerges clearly when one accounts for the effects of the negative background constant contribution to the canonical critical specific heat. We show that this same constant plays a significant role in determining the observed differences between the canonical and microcanonical specific heats of systems of finite size, in the critical region.

Journal Article↗