Exploring Vibrational Optical Activity with PyVib2

In this work we present a practical example of the automatic correlation of the vibrations of two molecules based on an approach which introduces a new formalism for comparing force fields in cartesian coordinates via the normal modes they entail. We consider two partially deuterated isotopomers of (+)-(R)-1-methylindane, a molecule the absolute configuration of which was successfully verified with vibrational optical activity. The isotopomers are obtained by substituting four hydrogen atoms either in the aromatic or in the aliphatic ring by deuterium atoms. This substitution gives rise to the mixing of the normal modes of the parent system. The automatic correlation of the vibrations will be demostrated with the PyVib2 program.