Abstract
Electronic states of superionic conductors such as alpha-AgI, Li3N, and the lithium sulfate superionic conducting glasses, were calculated by the DV-Xalpha cluster method. The movements of the cations were simulated by several model clusters with different positions of the moving cation. The net charge of moving cations and the total bond overlap population between the moving cation and the other ions were used for discussion of chemical bonding of the moving cation. In alpha-AgI and Li3N crystals, the total bond overlap population of the moving cation along the conduction path changed smaller than those of the other paths. On the other hand, the changes of the net charges of the moving cations were similar in any paths. Furthermore the relationship between ionic conductivity and the differential bond overlap population were discussed in the lithium sulfate superionic conducting glasses. In these glasses, the DBOP had good negative correlations with the ionic conductivities and positive correlations with the activation energies.
