Electronic structure and basic optical constants of TlHgBr3: Density functional theory calculations

Abstract We provide data of density functional theory (DFT) calculations of total and partial densities of states of TlHgBr3 using the method of augmented plane wave–local orbitals. The calculated density of states yields information regarding hybridization between the electronic states and on the chemical bonding of TlHgBr3. The DFT calculations predict that the principal contributors to the valence band (VB) of TlHgBr3 are 4p electronic states of bromine atoms at the central and upper regions of the band, with their slightly smaller input in other VB regions. Substantial contributions of 6s electronic states of thallium atoms lie at the upper part and bottom of the VB, and 6s states of mercury atoms occupy the bottom attributing to a specific electronic structure of TlHgBr3. The unoccupied Hg 6s electronic states, with somewhat lesser input of the unoccupied Br 4p states, contribute to the lower part of the conduction band (CB) of TlHgBr3. The theoretically derived electronic band structure demonstrates that the CB minimum and the VB maximum are positioned at the point Z of the Brillouin zone denoting a direct nature of band gap. Basic optical constants of TlHgBr3 are explored in the present work in relation to calculated electronic band structure.