Crystal field interactions within the Pr3+4f15d1 configuration

Abstract A new approach, based on the use of symmetry-adapted state basis and crystal field Hamiltonian, is proposed for handling calculations of the 4f15d1Pr3+ energy levels. The case of Pr3+ ions at sites of S4 symmetry is considered. In fact, the relevant 4f15d1 state basis and the crystal field Hamiltonian Hcf are adapted to the chain of groups R3±⊃Oh⊃D2d⊃S4 rather than to a given group in this chain. The emphasis is presently laid on the treatment of Hcf. A generic expression for the Hcf matrix elements in the considered symmetry-adapted state basis is given. As an application, the contribution of the part of Hcf concerned with the crystal field interactions with the 5d electron is calculated in terms of the new crystal field parameters.