Ab initio calculations of structure and thermodynamic properties of tetragonal-TiH2under high temperatures and pressures

Abstract

The structural and thermodynamic properties of tetragonal-TiH 2 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-TiH 2 such as thermal expansion coefficient, Debye temperature, heat capacity and Gruneisen parameters dependence of temperature and pressure in the range of 0–1000 K and 0–10 GPa are also presented, respectively.