Computing Gibbs free energy differences by interface pinning

Author(s)
Ulf R. Pedersen, Felix Hummel, Georg Kresse, Gerhard Kahl, Christoph Dellago
Abstract

We propose an approach for computing the Gibbs free energy difference between phases of a material. The method is based on the determination of the average force acting on interfaces that separate the two phases of interest. This force, which depends on the Gibbs free energy difference between the phases, is computed by applying an external harmonic field that couples to a parameter which specifies the two phases. Validated first for the Lennard-Jones model, we demonstrate the flexibility, efficiency, and practical applicability of this approach by computing the melting temperatures of sodium, magnesium, aluminum, and silicon at ambient pressure using density functional theory. Excellent agreement with experiment is found for all four elements, except for silicon, for which the melting temperature is, in agreement with previous simulations, seriously underestimated.

Organisation(s)
Computational Materials Physics, Department for Teacher Education, Computational and Soft Matter Physics
External organisation(s)
Technische Universität Wien, Center for Computational Materials Science, CMS
Journal
Physical Review B
Volume
88
No. of pages
5
ISSN
1098-0121
DOI
https://doi.org/10.1103/PhysRevB.88.094101
Publication date
09-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
103009 Solid state physics, 103015 Condensed matter, 103025 Quantum mechanics, 103036 Theoretical physics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/b439212f-fe36-4cec-a7f5-86dbe9838033