Electronic Structure of Ternary Ruthenium-Based Hydrides

Abstract

We have investigated the electronic structure and bonding characteristics of a series of ternary hydrides composed of transition metals (iron, ruthenium, osmium) and different alkaline-earth elements. Using first-principle methods to compute the electronic structure, the systematic investigation of this isostructural series of compounds allows us to establish chemical trends on different properties. We extend our investigation to the case of low-symmetry, low-hydrogen-coordination ruthenium-based hydrides. We were able to systematize the computed properties in terms of transition-metal−hydrogen and interlattice interactions. We found that the charge state of the transition metal correlates with the hydrogen site energy, indicating the importance of the charge redistribution in the molecular anions. The H site energy exhibits an interesting correlation with the hydride formation enthalpy. The formation enthalpy, from the elements, shows a correlation with the interlattice interaction energy, indicating the importance of the alkaline-earth sublattice.