THEORETICAL-STUDY OF THE VIBRATIONAL CIRCULAR-DICHROISM OF 1,3-DIDEUTERIOALLENE - COMPARISON OF METHODS

Vibrational rotational strengths are calculated for allene-1,3-d2 by using the fixed partial charge (FPC), localized molecular orbital (LMO), and atomic polar tensor (APT) models and the a priori theory of Stephens. The LMO model is implemented using semiempirical methods. The APT model and the a priori theory are implemented at the ab initio SCF level of approximation. Dipole strengths for allene-1,3-d2, -d0, and -d4 are simultaneously calculated. Dipole strengths predicted a priori are in reasonably good agreement with experimental values; the LMO and FPC models give similar and very different results, respectively. Rotational strengths calculated from the FPC, LMO, and APT models overall bear little resemblance to those calculated from the a priori theory. © 1990 American Chemical Society.