Energy density analysis of the chemical bond between atoms in perovskite-type hydrides

Atomization energy diagram is proposed for analyzing the chemical bond in the perovskite-type hydrides such as M 1 MgH3 (Ml = Na, K, Rb). RbCaH3, CaNiH3 and SrPdH3. The atomization energies of hydrogen and metal atoms in the hydrides are evaluated theoretically by the energy density analysis (EDA) of the total energy, and used for the construction of the atomization energy diagram. Every hydride can be located in such an energy diagram, although there are differences in the nature of the chemical bond among the hydrides. When the hydrides have a resemblance in the chemical bond, their locations are close to each other in the diagram. The role of constituent elements in the hydride is understood well with the aid of this diagram. For comparison, the atornization energy diagram is shown for the perovskite-type oxides. (C) 2007 Elsevier B.V. All rights reserved.