Electronic structure, hydrogen site occupation and phase stability of Ti3Al upon hydrogenation

Hydrogen-site occupancy, phase stability and heat of formation of Ti3Al upon hydrogenation are studied through the calculation of electronic structure and total energy using the Linear Muffin Tin Orbital method. Our calculations show that hydrogen favours the body centered octahedral position over the edge-centered octahedral position in agreement with the experimental findings. Our calculations indicate a drastic deformation of the conduction band of Ti3Al when hydrogen is included in the system and the hydrogen exhibits strong interaction with Ti atoms. The calculated band structure and DOS of Ti3AlH are also presented. In addition the structural stability is discussed in terms of DOS at the Fermi level and pseudo-gap concepts