Theoretical study of electronic structure and spectroscopic properties of the TlO molecule

Abstract

The electronic structure and properties of the thallium monoxide (TlO) molecule, as well as its cation and anion, have been systematically studied using both the relativistic Fock-space coupled cluster method with full inclusion of connected triple excitations and the density functional theory. For the first time, detailed data on the low-lying electronic states of TlO, its cation, and anion have been obtained. The dissociation energies of these systems, the adiabatic electron affinity and vertical ionization potential of TlO, as well as its dipole moment and components of the static polarizability tensor have been calculated. It is shown that the ground electronic state of TlO$^+$ cation is unbound. The obtained characteristics of TlO are highly relevant for interpreting experimental thermochromatography data on compounds of thallium and its superheavy homologue nihonium (element 113).