Trends in hydride formation energies for magnesium-3d transition metal alloys

We use density functional theory to investigate the hydride formation in magnesium-3d transition metal (TM) alloys of potential interest as hydrogen storage media. We use a body-centered tetragonal unit cell as a tentative model of the MgTM alloys and a Perovskite structure for the MgTMH3 hydrides. We find large variations in the hydride heat of formation from one alloy to the next, which correlate with the characteristics of the transition metal d-band.