An ab initio study of spectroscopic and thermodynamic characteristics of MgH2 and TiC systems

In this investigation, structural, dynamical and thermodynamic characteristics of magnesium hydride (MgH2) and titanium carbide (TiC) are performed through first principle calculations based on the density functional theory (DFT). The lattice dynamics were investigated using the finite displacement supercell approach and thermodynamic calculations were carried out using the harmonic approximation. The modes of vibrations were studied to explore the behavior of individual atoms. The minimum hydrogen release temperature was noted to be Tc = 719 K when only electronic and vibrational free energies of MgH2 and TiC systems are considered at pressure of 1 bar. However, a remarkable reduction in hydrogen release temperature is noticed in MgH2 and TiC system i.e. Tc = 321 K (fall of 398 K) by including all the contributions of free energies (i.e. electronic, translational, rotational and vibrational) of hydrogen molecule. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.