BONDING NATURE OF INTERCALATION COMPOUNDS M1/3TiS2 (M=TRANSITION-METAL ATOM, SILVER ATOM, ALKALI-METAL ATOM)

Abstract

Self-consistent LAPW band calculations have been carried out systematically for intercalation compounds M 1/3 TiS 2 (M=transition metal, silver, alkali metal) in order to clarify bonding nature between the guest atoms and the host TiS 2. In transition-metal intercalates the guest 3d states hybridize with the S 3p states as well as the Ti 3d states. As the result covalent bonds are formed between the guest 3d and S 3p states, conserving the covalent bonds between the Ti 3d and S 3p states of the host. In Ag 1/3 TiS 2 the Ag 4d states hybridize strongly with the S 3p state and destroy the host covalent bonds between the Ti 3d and S 3p states. In Li 1/3 TiS 2 and K 1/3 TiS 2 there is little hybridization between the guest 2s or 4s states and the host Ti 3d or S 3p states. Cohesive properties of M 1/3 TiS 2 compounds, including stacking structures of the guest atoms, are discussed on the basis of the total energy calculation.