The correlation of intermolecular effects in the vibration spectra of BF3 with alterations in its quadratic valence force field

The effect of weak and specific intermolecular interactions in the vibration spectra of molecules is considered and correlated with alterations in the potential energy of the molecule via the force field. The approach, which follows a previously developed method [3], shows how best to choose the perturbations in order to reproduce the intermolecular interaction and keep the internal consistency of the force field. The vibrational calculation is exemplified for XY₃molecules with D_3h symmetry and applied to the boron trifluoride molecule.