Density functional analysis of the electronic structure of Cs9InO4:Evidence for the presence of a Cs– anion

Abstract The complex oxoindate Cs9InO4, described by the electron counting (Cs+)8Cs—[(In3+)(O2–)4] + 2e−, consists of InO4 tetrahedra and Cs(Cs)16 clusters. In each Cs(Cs)16 cluster a Cs atom is located at the center of the (Cs)16 cage, and the Cs9 sublattice of Cs9InO4 is obtained from the face- and edge-sharing of the Cs(Cs)16 clusters. To examine the charge density distribution among the Cs atoms in each Cs(Cs)16 cluster, density functional calculations were carried out for Cs9InO4, and the results were analyzed. Our analysis indicates that, to a first approximation, the Cs atom located at the center of each Cs(Cs)16 is best described as Cs– anion.