By using the irreducible tensor operator method, two corollaries have been derived from generalized Wigner-Eckart theorem and the results associated with the corollaries are obtained. For the. d2 ions in a trigonally distorted cubic crystal field, the effective method dealing with overall problems of D, g‖, g⊥ and absorption spectrum has been suggested on the basis of unified model, in which all possible interaction of Vc and (Vtr + Hs) have been considered.In application to vanadium corundum, successful results in agreement with the experiments are obtained by overall fitting of the theoretical values to the observed values of D,g‖, g⊥ and absorption spectrum.The problems concerned in our model and methods have been discussed.