Difference of electronic structures between NaInO2 and NaInS2

The electronic structures of NaInO2 and NaInS2 are calculated by using the discrete variational X alpha method on model clusters. For NaInO2, it is fo und that the In-O bonding is not perfectly ionic but partially covalent bec ause of the hybridization between O 2s, 2p and In 5s, 5p orbitals in the el ectron-occupied band. However, the overlapping of Na 3s, 3p orbitals with O 2s, 2p orbitals is very weak. On the other hand, Na 3s, 3p orbitals of NaI nS2 relatively hybridize with S 3s, 3p orbitals, not only In 5s and 5p orbi tals. These results show that the nature of the chemical properties of NaIn S2 is more covalent, compared with NaInO2.