Calculation of electro-optical parameters, a new approach. Part III. Applications to X₂CZ molecules (X=H, F, Cl, Br and Z=O, S)

Abstract

Calculations of electro-optical parameters by the modified first order approximation (MFOA) method have been extended to X₂CZ (X=H, F, Cl, Br; Z=O, S) molecules with a view to investigate the transferability of these parameters. The diagonal and cross elements of the bond moment derivative matrix have been evaluated. Unique values of μ_C-X are obtained for the A₁ species. The bond moment derivatives are found to be transferable among A₁ and B₁ species. Transferability of the μ_C-Z in B₁ and B₂ species is obtained for thiocarbonyl halides. Bond moment derivatives with respect to angle deformations are not found to be very significant whereas other cross elements of the bond moment derivative matrix are found to be of high magnitude.