Zero‐field splitting of ⁶S(d⁵) ions in tetragonal and rhombic symmetry. II. Application of complete d‐electron calculations to the zero‐field splitting in Mn:MnF₂ and Mn:ZnF₂

The results of a complete d‐electron calculation for configuration 3d 5 of orthorhombic symmetry are applied to a study of zero‐field splitting in Mn 2+ :MnF 2 and Mn 2+ :ZnF 2 . The parameters are determined from the optical spectra of the crystals by a least squares fit and adjusted by conditions governing the zero‐field splitting. The results for Mn 2+ :ZnF 2 , D = −180.0 × 10 −4 cm −1 , E = −42.2 × 10 −4 cm −1 are in excellent agreement with the experimental values D = (−186 ± 7.5) × 10 −4 cm −1 , E = (−41 ± 12.5) × 10 −4 cm −1 . The data for Mn 2+ :MnF 2 are used to estimate the unknown covalency contribution. All contributions fit into a regular and consistent pattern.