Toward a Global Analysis Method Based on Anharmonic Ladder Operators: Application to Hydrogen Sulfide (H232S)
journal contributionposted on 24.12.2015, 00:00 by Miguel Carvajal, Renato Lemus
A novel model for the analysis of the rovibrational structure of a molecule based on anharmonic ladder operators associated with the vibrational degrees of freedom is presented. This is devised as an alternative method for the global spectral analysis of rovibrational data considering vibrational anharmonicities from the outset. The present method is thought up with an effective rovibrational Hamiltonian written in terms of angular momentum components and anharmonic Morse ladder operators, associated with rotational and vibrational degrees of freedom, respectively. The resulting Hamiltonian is diagonalized in a symmetry-adapted basis set expressed as a product of rotational states and individual 1D-Morse wave functions for each local vibrational degree of freedom. This approach has been successfully applied to the study of the vibrational structure (up to polyad 14) and the rovibrational structure (up to polyad 2 and Jmax = 20) of hydrogen sulfide. It was shown that this new global analysis formalism is able to reduce considerably the number of fitted parameters with respect to the spectral analysis carried out for separate polyads.