Chemical bonding features of the ternary alkali metal platinum and palladium hydrides

Abstract

Numerous ternary complex hydrides based on alkali and transition metals have been synthesized in recent years. These compounds show novel crystal structures and a variety of H coordinations around the transition metal, some of them unusual. The coexistence of ionic and covalent chemical bonds in such hydrides is also remarkable. In this article we have investigated, from first principles, the electronic structure of some palladium and platinum ternary hydrides. By means of the augmented plane wave method we have calculated the energy bands, density of states, and the partial wave and symmetry analysis of the density of states at each atomic site. Using these results we discuss the features of the electronic structure and chemical bonding in hydrides such as A2TH4 (A=Na,K; T=Pd,Pt), which are found to be semiconductors. We discuss the trends in the electronic properties of palladium and platinum hydrides with linear, square planar, and octahedral H coordinations. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 80: 141–152, 2000