The high-order perturbation formulas based on the two-mechanism model are applied to calculate the g factors g// and g⊥ of the tetragonal (MoO4)3 Symbolm@@ center in BaWO4 crystal irradiated by X-ray. The model contains the contributions to g factors from both the crystal-field (CF) mechanism and charge-transfer (CT) mechanism (note: CT mechanism is neglected in the extensively-used CF theory). The calculated results are reasonably consistent with the experimental values. The calculations show that for the exact calculations of g factors of high valence state dn ions in crystals, the contributions due to CT mechanism should also be considered. The local structure of (MoO4)3 Symbolm@@ center is also estimated from the calculation.
