Explanation of the Optical Spectra and Spin-Hamiltonian Parameters for Nickel(II) in Cadmium Bromide Crystal

Based on crystal- and ligand-field theory, double-spin-orbital coupling approach was used to analyze the crystal-field energy levels and spin-Hamiltonian parameters of $Ni^{2+}$ ion at trigonal site in $CdBr_2$. The local lattice distortion (Δ R and $τ_{Ni^{2+}}$) is estimated from the crystal field parameters; the crystal field energy Hamiltonian was diagonalized in the full basis consisting of 45 wave functions of the $Ni^{2+}$ ion. Results of calculations are in good agreement with experimental data. The reasonableness of the theoretical results is discussed.