Ab initio study of lattice dynamics and thermal equation of state of Ni

Lattice dynamics and thermal equation of state of fcc nickel have been studied in the framework of density functional perturbation theory. The influence of the GGA + U on the structure is considered. The calculated phonon dispersion curve accords excellently with the experimental data. Within the quasiharmonic approximation, the thermal equation of state, thermal expansion coefficient, thermal pressure, bulk moduli and Debye temperature are well reproduced. The thermal properties confirm the available experimental data and are extended to a wider pressure and temperature range. (C) 2011 Elsevier B.V. All rights reserved.