D. Papousek et al., DENSITY-FUNCTIONAL COMPUTATIONS OF THE DIPOLE-MOMENT DERIVATIVES FOR HALOGENATED METHANES, Journal of physical chemistry, 99(42), 1995, pp. 15387-15395
Electric dipole moments for the equilibrium molecular structures and t
heir derivatives along the symmetry coordinates of vibration were comp
uted for CH2F2, CD2F2, CH2Cl2, CD2Cl2, CF2Cl2, CH3F, CD3F, CH3Cl, CD3C
l, CHF3, CDF3, CHCl3, CDCl3, CFCl3, CF3Cl, CF4, and CCl4 by means of t
he deMon density functional program (St-Amant, A.; Salahub, D. R. Chem
. Phys. Lett. 1990, 169, 387). A satisfactory agreement was found betw
een the experimental and computed dipole moments for the equilibrium m
olecular structures. Perfect agreement was found between the rotationa
l corrections to the dipole moment derivatives calculated by deMon and
those obtained independently from the permanent dipole moment and the
orthogonality relations between the symmetry coordinates and the rota
tional coordinates. Using force constants which are available from the
literature, derivatives of the dipole moments were transformed into t
he representation of the normal coordinates of vibration, and the resu
lts were compared with the experimental data on the infrared intensiti
es. Density functional computations provide reliable information on th
e relations between the signs of the dipole moment derivatives and in
most cases also on their absolute values in the series of investigated
molecules.