Ab initio calculations of structure and thermodynamic properties of tetragonal-TiH₂ under high temperatures and pressures

Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900, P.R. China

^a e-mail: xiankunliu@gmail.com

Received: 1 July 2013
Accepted: 22 August 2013
Published online: 3 October 2013

Abstract

The structural and thermodynamic properties of tetragonal-TiH₂ under high temperatures and pressures are investigated by Ab initio calculations based on pseudo-potential plane-wave density functional theory method within using the generalized gradient approximation (GGA) and quasi-harmonic Debye model. Some ground state properties such as lattice constants, bulk modulus and elastic constants are good agreement with the available experimental results and other theoretical data. Through the quasiharmonic Debye model, in which the phononic effects are considered, the thermodynamic properties of tetragonal-TiH₂ such as thermal expansion coefficient, Debye temperature, heat capacity and Grüneisen parameters dependence of temperature and pressure in the range of 0–1000 K and 0–10 GPa are also presented, respectively.