Perturbation calculation of thermodynamic density of states

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Physical Review E

DOI:https://doi.org/10.1103/PhysRevE.84.061116· OSTI ID:1034018

Brown, Greg ^[1]; Schulthess, Thomas C ^[1]; Nicholson, Don M ^[1]; Eisenbach, Markus ^[1]; Stocks, George Malcolm ^[1]

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1. ORNL

The density of states g( ) is frequently used to calculate the temperature-dependent properties of a thermodynamic system. Here a derivation is given for calculating the warped density of states g ( ) resulting from the addition of a perturbation. The method is validated for a classical Heisenberg model of bcc Fe and the errors in the free energy are shown to be second order in the perturbation. Taking the perturbation to be the difference between a first-principles quantum-mechanical energy and a corresponding classical energy, this method can significantly reduce the computational effort required to calculate g( ) for quantum systems using the Wang-Landau approach.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1034018
• Journal Information: Physical Review E, Vol. 84, Issue 6; ISSN 1539-3755
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
FREE ENERGY
HEISENBERG MODEL
THERMODYNAMICS