Study of the Perpendicular Band Intensities of the CH Chromophore in CHCl3, CHBr3, and CHI3 with Three-Dimensional Dipole Moment Surface from Density Functional Calculations

Combined perturbative-variational investigation of the vibrations of CHBr3 and CDBr3

A full dimensional vibrational treatment of CHBr(3) and CDBr(3) using Van Vleck perturbation theory followed by a variational calculation is presented. The calculation of a force field, and its adjustment for better match with experiment, is discussed. The computed eigenstates and spectral features are compared to experiment. Changes in intensities of the nu(1) and 2nu(4) bands upon simple alterations of the dipole moment expansion are described.