p-d hybridization of noble metal halides

The eletronic band calculations of noble metal halides are studied to make the high ionic conducting origin of silver and cupper ions clear using the tight-binding method. The d bands of Ag ions are much more weakly coupled w ith the p bands of halogen ions, while those of Cu ions are much more stron gly coupled with the p bands. The strength of p-d hybridization is discusse d to connect with the activation energy for the ionic conduction. It is sho wn that the high ionic conductivity of AgX primary stems from combination o f the deformability of the d shell and the weakness of the p-d hybridizatio n.