The geometry optimization of C28H3Cl, C28H2Cl2, C28HCl3, CH3Cl, CH2Cl2, CHCl3 have been performed by INDO series methods, C28H3Cl, C28HCl3, CH3Cl, CHCl3 are C3v symmetry and C28H2Cl2, CH2Cl2 are C2v symmetry. The ground states of above six molecules are stable closed- shell molecules. On the base of these geometries, the electronic spectra of above molecules have been calculated. The electronic spectra of C28H4-nCln(n=1~3) are theoretical predictions.

Key words: INTERMEDIATE NEGLECT OF DIFFERENTIAL OVERLAP APPROXIMATION (IND, ELECTRONIC SPECTROSCOPY