AB-INITIO CALCULATIONS OF ANHARMONIC VIBRATIONAL TRANSITION INTENSITIES OF TRANS-2,3-DIDEUTERIOOXIRANE

The quartic force field and the cubic dipole moment surface are calcul ated for trans-2,3-dideuteriooxirane at the self-consistent field and the second order Moller-Plesset levels of theory using a triple zeta p lus two polarization functions basis set. Contact transformation theor y is used to determine the corresponding anharmonic vibrtional frequen cies and intensities. Inclusion of anharmonicity improves agreement of the calculated frequencies and intensities with their experimental co unterparts. The anharmonic corrections are much more sensitive to corr elation effects for intensities than for frequencies. (C) 1995 America n Institute of Physics.