A global potential energy surface describing the N((2)D) + H2O reaction and a quasiclassical trajectory study of the reaction to NH + OH.

We report a global potential energy surface (PES) for the N((2)D) + H2O reaction based on fitting roughly 312 000 UCCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. Quasiclassical trajectory calculations of the N((2)D) + H2O(D2O) reaction with focus on the NH(D) + OH(D) exit channel are performed. An analysis of the internal-state distributions shows that the NH(D) fragment has more internal energy, both rotational and vibrational than the OH(D) fragment, in good agreement with experiment. This difference is traced to nonstatistical dynamics.