An analysis of the T⊗(e+t₂) Jahn-Teller system with strong coupling

Abstract

The T(X)(e+t2) Jahn-Teller system is studied in the strong-coupling approximation on a cluster model by transformation methods. An energy-minimisation procedure is used to show that the system will be localised in potential energy minima having either tetragonal, trigonal or orthorhombic symmetry depending upon the strengths of the e and t2 coupling constants. Detailed results are given for the orthorhombic case to underline the physical processes involved in the Jahn-Teller effect and provide a detailed mathematical framework for the calculation of other properties of the system (e.g. first- and second-order reduction factors, random-strain effects).