An algebraic approach to calculating rotation-vibration spectra of polyatomic molecules

Abstract

An approach for calculating electric dipole intensities of transitions to highly vibrationally excited states in polyatomic molecules is presented. We apply canonical Van Vleck perturbation theory (CVPT) to the space fixed dipole moment operator, where both the rotational and vibrational coordinate dependencies are expressed in terms of boson creation and annihilation operators. This approach is general and can be applied to a large class of polyatomic molecules. Theoretical spectra are presented for H2O with T rot = 300 K and H2CO with T rot = 10 K.