Internal dynamics of (H2O)(2) and (D2O)(2) dimers: I. Classification of stationary states with account of inversion and exchange motions

摘要

The geometric symmetry group of the internal dynamics of (H2O)(2) and (D2O)(2) dimers taking into account two nonrigid motions with the lowest energy barriers is obtained. The motions are the inversion motion (or the acceptor switching) and the exchange motion of the acceptor and donor via an intermediate trans configuration. On this basis, a rigorous model for the description of such motions in the ground electronic-vibrational state is constructed. The model leads to a simple algebraic scheme for the calculation of both the positions of levels in the energy spectrum and the intensities of transitions between them. The classification of stationary states that takes into account the geometry of inversion and exchange motions is considered.