Quadratic Jahn-Teller coupling in octahedral systems

Abstract

In this paper Jahn-Teller vibronic coupling calculations are presented for the general case [Γ_8g × e_g ] in O_h * symmetry. The hamiltonian employed is complete up to terms quadratic in vibrational coordinates q_θ and q_ε which span the ν₂(e_g ) mode of MF₆ systems. Calculational details are discussed. It is concluded that, in agreement with previously reported spectroscopic data for ReF₆ and IrF₆, quadratic terms in the vibronic interaction are essential (both qualitatively and quantitatively) to the complete understanding of intra-state vibronic coupling in transition metal hexafluorides.