The preferred jahn-teller coupling for T states of cubic dx systems

Abstract

The angular overlap model is used to make predictions of the preferred vibrational coupling for Jahn-Teller active T states of cubic ( O h ML 6 and T d ML 4) d x systems. For the 2,5 T 2(g) states of d 1, d 4, d 6 and d 9and for the 3,4 T 2(g) states of d 2, d 3, d 7 and d 8, where only a single state of the given spin, S, and irreducible representation, Γ, occurs, clear predictions emerge, and ϵ g (or ϵ) coupling should be dominant for all cases except 2,5 T 2g O h(for which E JT for ϵ g and τ 2gcoupling are likely to be of comparable magnitude). For the 3,4 T 1(g) states of d 2, d 3, d 7 and d 8, two admixed states always arise, but for the d 2 and d 7 O h systems and for the d 3 and d 8 T d systems, coupling to ϵ g or ϵ, respectively, ought to be predominant, irrespective of the strength of the ligand field. For the d 2 and d 7 T d systems and for the d 3 and d 8 O h systems, however, a more complex situation results and the preferred coupling is markedly dependent upon the ligand field strength.