The stability and bonding of the ternary complex K2PtCl6 structure hydrides is discussed using first principles density functional calculations. The cohesion is dominated by ionic contributions, but ligand field effects are important, and are responsible for the 18-electron rule. Similarities to oxides are discussed in terms of the electronic structure. However, phonon calculations for Sr2RuH6 also show differences, particularly in the polarizability of the RuH6 octahedra. Nevertheless, the yet to be made compounds Pb2RuH6 and Be2FeH6 are possible ferroelectrics. The electronic structure and magnetic properties of the decomposition product, FeBe2 are reported. Implications of the results for H storage are discussed.
@article{arxiv.cond-mat/0406506,
title = {Stability and electronic structure of the complex K$_2$PtCl$_6$ structure-type hydrides},
author = {S. V. Halilov and D. J. Singh and M. Gupta and R. Gupta},
journal= {arXiv preprint arXiv:cond-mat/0406506},
year = {2009}
}