Heats of formation of 3d and 4d transition metal hydrides

One electron energy spectra are used to explain the heats of formation of stoichiometric transition metal hydrides across the 3d and 4d rows. The trends agree reasonably with existing experimental information. The magnitudes are predominantly (but not exclusively) determined by the formation of a metal-H bonding band. In contrast to the screened proton model, the result is not directly related to the Fermi level density of states.