MOLECULAR-STRUCTURE AND VIBRATIONAL IR-SPECTRUM OF FORMAMIDE REVISITED - AB-INITIO POST-HARTREE-FOCK STUDY

The results of high-level ab initio calculations using a 6-311G(3df,2p) basis set with electron correlation included at the second-order Moller-Plesset perturbation theory are reported for molecular parameters (geometry, dipole moment, rotational constants) and the vibrational IR spectrum (harmonic wavenumbers, absolute intensities) of formamide. The present calculations predict such a small deviation from the planarity of the molecule that it should be considered as a planar system. Computed dipole moment, rotational constants and the vibrational IR spectra of formamide and its deuterated species agree very well with the available experimental data.