Normal coordinate analysis of the zero-field splitting in octahedral NiF^4-₆

Abstract

Ab initio calculations including spin-orbit coupled configuration interaction, are used to create a map of the zero-field splitting as a function of the normal coordinates in octahedral NiF^4- ₆. Linear terms of the splitting with respect to distortion modes are superposed to give a resultant splitting pattern. Only the E_g and the T_2g modes are found to contribute. A series of 100 random distortions is performed in order to compare estimated and calculated values of the zero-field splitting. The relative error is below 30% and the ordering of the levels is correct for all distortions.