Accurate Potential Energy Surfaces for the Three Lowest Electronic States of N(2D) + H2(X1∑g+) Scattering Reaction

The three lowest full three-dimensional adiabatic and three diabatic global potential energy surfaces are reported for the title system. The accurate ab initio method (MCSCF/MRCI) with larger basis sets (aug-cc-pVQZ) is used to reduce the adiabatic potential energies, and the global adiabatic potential energy surfaces are deduced by a three-dimensional B-spline fitting method. The conical intersections and the mixing angles between the lowest three adiabatic potential energy surfaces are precisely studied. The most possible nonadiabatic reaction pathways are predicted, i.e., N­(2D) + H2(X1∑g+) → NH2(22A′) → CI (12A′–22A′) → NH2(12A′) → CI (12A″–12A′) → NH2(12A″) → NH­(X3∑–) + H­(2S). The products of the first excited state (NH­(a1Δ) + H­(2S)) and the second excited state (NH­(b1∑g+) + H­(2S)) can be generated in these nonadiabatic reaction pathways too.