Abstract

The bonding and electronic structure in one- and two-dimensional copper-vanadium sulfides, based on tight binding band calculations, has been studied. Theoretical evidence for the existence of weak donor-acceptor interactions from the d10 copper(I) ion toward the empty d orbitals of VV is discussed. Maximization of the number of d10-d0 interactions explains the structural choice among alternative distributions of the transition metal ions within the sulfide matrix. The double chains of Ba2Cu3VS6 and the layers of KCu2VS4 have an electron deficiency associated with the presence of hypervalent sulfur bridges that slightly enhances the Cu ? V interaction.