Studies of the defect structure for Mn2+ in KTaO3 crystal from the calculation of EPR zero-field splitting

There are several mistakes in the recent paper about the theoretical studies of defect structure for Mn2+ ion at the 12-fold tetrakaidecahedral K+ site in KTaO3 by calculating the spin Hamiltonian (SH) parameters, so the calculated defect structure (which is smaller than those obtained from the local density approximation (LDA) method, density functional theory in the generalized gradient approximation (GGA) and the dipole moment study (DMS)) is doubtful. Therefore, we restudy the defect structure in this paper by using the reasonable expressions and parameters. The present result is in agreement with those based on LDA, GGA and DMS methods and can be regarded as reasonable. It appears that the reliability of the defect structure of impurity center determined from the calculation of SH parameter depends strongly upon reasonableness of the used expressions and parameters. (c) 2006 Elsevier B.V. All rights reserved.