On the choice electronic structure method to calculate the quartic potential energy surface for the vibrational calculation of polyatomic molecules

A systematic study is made on the effects of electronic structure calculations on anharmonic spectra of polyatomic molecules. Our study is focused on the choice of electronic structure method and basis set to calculate the quartic potential energy surface (PES). We used two correlated methods Moller-Plesset perturbation theory and density functional theory with B3LYP functional and two different types of basis sets, aug-cc-pVTZ and 6-311G(2d, 2p) to calculate the PES and linear DMS. For the vibrational description, we used the vibrational self-consistent field theory and the vibrational coupled cluster theory in bosonic representation.