CHARACTERIZATION OF THE MINIMUM ENERGY PATH FOR CH(X(2)PI)+N2(X(1)SIGMA(G)(+))-]HCN(X(1)SIGMA(+))+N(S-4)

Previous work by Manaa and Yarkony has characterized the doublet-quartet crossing region for the title reaction. In the present work, the minimum energy pathways for addition of CH(2PI) to N2 on the doublet surface and for dissociation of HCNN to HCN+N(4S) on the quartet surface are characterized using complete active space SCF(CASSCF) and internally contracted CI (ICCI) methods. The doublet-quartet crossing region is found to be separated from reactants by a barrier of almost-equal-to 18 kcal/mol and from products by a barrier of almost-equal-to 23 kcal/mol.