Normal coordinate treatment of 1-methylthymine in the crystalline state: Use of the ultraviolet resonance Raman intensities to improve the vibrational force field

Abstract

A general valence force field for 1-methylthymine (1MeT) in the isolated state has been unequivocally determined from the calculation of both the frequencies and the relative ultraviolet resonance Raman intensities arising from the first lowest lying vibronic transitions. In a second step, the normal modes were derived for the crystalline state using the previously determined in-plane force field and an out-of-plane force field was deduced.