POTENTIAL-ENERGY SURFACE OF THE O(D-1)-]2NO, O-2+N-2 REACTIONS(N2O)

Using the Moller-Plesset method the ab initio N2O2 potential energy su rface (PES) is calculated in order to study the exothermic singlet sta te reaction channels O(D-1) + N2O --> 2NO, O-2(a 1 Delta(g)) + N-2. Ac cording to the results of the calculation, the O(D-1) + N2O --> 2NO ch annel PES demonstrates the main energy release in the entrance valley. In this channel a wide interval of angle O(D-1)NN approach angles aro und the collinear configuration is easily accessible, but the minimum energy approach is not collinear. The O(D-1) + N2O --> O-2(a 1 Delta(g )) + N-2 channel is strongly noncollinear, as the minimum energy angle O(D-1)ON approach angle is close to 90 degrees. The main energy relea se of this channel takes place in the exit valley. The results of the ab initio calculations have been used to construct an analytical model potential that describes roughly the main features of the N2O2 PES an d can be used in the dynamical studies of both O(D-1) + N2O reaction c hannels.