A CLASSICAL MECHANICAL STUDY OF THE GEOMETRIC PHASE EFFECT IN CHEMICAL-REACTIONS

The general hyperspherical formulation of the vector potential arising due to an arbitrary position of the conical intersection of the adiab atic potential energy hypersurfaces of an A + BC type reactive system is considered. We treat the operators in the Hamiltonian (with or with out vector potential) as classical variables and see the same directio n of the relative shift in the peak position of the rotational distrib ution as in the quantum mechanical (QM) calculations by Kuppermann and Wu. Though the absolute peak position of the rotational distributions (with and without geometric phase) obtained by quasi-classical trajec tory (QCT) calculations differs from this QM calculation, the physical effect is the same. The present calculations require little computati onal effort. (C) 1998 Published by Elsevier Science B.V.