Local mode vibrations of water

Abstract

Classical trajectory calculations on a realistic potential for the stretching vibrations of the water molecule are used to demonstrate the existence of stable local vibrational modes, which occur in degenerate pairs. The proportion of phase space occupied by such modes increases with increasing energy, with a clearly characterized (0, 2) local state in a local quantum number assignment. It is argued that quantum mechanical corrections will lead to a local mode splitting which is predicted to decrease in magnitude along any given stretching vibrational progression, and to be larger for a given quantum state of D₂O than for H₂O.