Theoretical study on the zero field splitting and dopant position of Mn2+ in KH3(SeO3)2 single crystal

In the present paper theoretical methods have been employed to investigate the zero field splitting (ZFS) parameter. The superposition model (SPM) with the microscopic spin-Hamiltonian theory and the coefficient of fractional parentage has been employed to investigate the dopant (manganese II) substitution in the potassium trihydrogen selenite (PTS) single crystal. The ZFS parameter by using the computational method of ORCA program package developed by Neese et al. has also been determined. The contribution of SOC (spin–orbit coupling) has been taken into consideration. The approach of CP (Coupled-Perturbed) method is found to be more appropriate than PK (Pederson–Khanna) method in the evaluation of ZFS for Mn(II) ion. The theoretical predictions of the zero field splitting (ZFS) parameter D on the basis of the above methodology has been compared with the experimental results. The theoretical results are appropriate with the experimental ones and indicate the interstitial occupancy of Mn2+ ion in the host matrix.