STRONG SHIFTS IN DIABATIC NONDYNAMIC ELECTRON CORRELATIONS CAUSE CONICAL INTERSECTION BETWEEN LOW-LYING CLOSED-SHELL ADIABATIC SINGLETS OF LIKE SYMMETRY IN OZONE

Using the quantum chemical construction of diabatic states from adiaba tic states formulated in the subsequent paper, the lowest two 1A1 stat es of ozone are expressed in terms of its diabatic components and the interaction matrix H(ij) between them is determined. An analysis of th e electronic structure of the diabatic states leads to an understandin g of the reasons for the sip changes in DELTAH and H12 and, hence, for the conical intersection between these two low-lying closed-shell adi abatic states of like symmetry.