The geometric phase effect on differential cross sections in chemical reactions: a classical mechanical approach

The considerable agreement between experimental and theoretical product rotational state distributions for the D + H2 reaction obtained with the inclusion of the geometric phase effect has created interest to see the influence of it on differential cross sections. Using the general hyperspherical formulation of the vector potential arising due to an arbitrary position of the conical intersection of the adiabatic potential energy hypersurfaces, we have calculated the distribution of scattering angles. This study has been carried out by quasi-classical trajectory calculations which require little computational effort. The features obtained by our study are qualitatively the same as those obtained quantum mechanically by Kuppermann and Wu.