Direct calculation of the solid-liquid Gibbs free energy difference in a single equilibrium simulation0

Category: Scientific Highlights

An Interface-Pinning-Method by Ulf Rørbæk Pedersen

ABSTRACT:

Computing phase diagrams of model systems is an essential part of computational condensed matter physics. In this paper, we discuss in detail the interface pinning (IP) method for calculation of the Gibbs free energy difference between a solid and a liquid. This is done in a single equilibrium simulation by applying a harmonic field that biases the system towards two-phase configurations. The Gibbs free energy difference between the phases is determined from the average force that the applied field exerts on the system. As a test system, we study the Lennard-Jones model. It is shown that the coexistence line can be computed efficiently to a high precision when the IP method is combined with the Newton-Raphson method for finding roots. Statistical and systematic errors are investigated. Advantages and drawbacks of the IP method are discussed. The high pressure part of the temperature-density coexistence region is outlined by isomorphs.

Visit Vienna Technical University's Website to watch a Video of "Interface-Pinning"

Visit the Ulf Pedersen's website for more videos.

Pedersen, Ulf R. 2013
Direct calculation of the solid-liquid Gibbs free energy difference in a single equilibrium simulation
The Journal of Chemical Physics 139 10 -
[Abstract] [BibTeX] [doi]

Other Recent ViCoM Publications

---