Gamma-point lattice free energy estimates from O1 force calculations.
We present a new method for estimating the vibrational free energy of crystal (and molecular) structures employing only a single force calculation, for a particularly displaced configuration, in addition to the calculation of the ground state configuration. This displacement vector is the sum of the phonon eigenvectors obtained from a fast-relative to, e.g., density-functional theory (DFT)-Hessian calculation using interatomic potentials. These potentials are based here on effective charges obtained from a DFT calculation of the ground state electronic charge density but could also be based on other, e.g., empiric approaches.
Voss
Johannes
J
Materials Research Department, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, 4000 Roskilde, Denmark. johannes.voss@risoe.dk
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Tejs
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