Abstract
A study of the electronic structure and chemical bonding of the transition-metal intercalated titanium disulfide, MTiS2 (M = Cr and Fe), is performed by a first-principles molecular-orbital method using a model cluster composed of 75 atoms. The discrete-variational (DV)-Xα method was employed and Mulliken’s population analyses were thoroughly conducted. The intercalation in the so-called “van-der-Waals gap” is found to change the local electronic structure significantly in the following manner: The net charge of the intercalated M-layer is decreased by 0.559 and 0.307 when M = Cr and Fe, respectively. The bond overlap population (BOP), a measure of the covalent bond-strength, decreases by approximately 20% as for the Ti–S bond. Both the BOPs of the Cr–S and Fe–S bonds are found to be as large as that of the Ti–S bond.
