ALGEBRAIC APPROACH FOR AN ACCURATE SIMULATION OF CO2 RAMAN SPECTRA

Abstract

We present an accurate simulation of the Raman spectrum of the carbon dioxide molecule in the 1150--1500~cm$^{-1}$ spectral range, comparing the results obtained using different polyad schemes. We first determine an optimal set of Hamiltonian interactions for the three different polyad schemes to after fit the 178 experimental term energies found in the literature. Thereafter, using a Taylor series expansion of the mean polarizability in terms of normal mode coordinates, we perform an additional canonical transformation followed by an anharmonization procedure and a fit to a subset of experimental transition moments. Once these steps are accomplished, the Raman spectrum of CO$_2$ is simulated and compared with the experiment.