The electronic energies of hydrogenated silicon vacancy which has Td symmetry are calculated. Using the method of completely neglecting of differential overlap (CNDO), we find the probability of the formation of the hydride quartet, and the effect of interaction between four SiH units in the model. We conclude that the hydride quartet complex is a more plausible model for the hydrogenated vacancy in crystalline silicon than that with four SiH bonds unrelated one another.