Inelastic scattering of the NCO(X2Pi) radical with the He atom on an ab initio potential energy surface.

The 2 A' and 2 A" adiabatic potential energy surfaces for the He-NCO(X 2 Π) van der Waals system are obtained by the partially spin-restricted coupled cluster method with single, double, and noniterated triple excitations (RCCSD(T)). The ab initio potentials are fit to analytical expressions, and scattering and bound state calculations are performed for a rigid NCO( 2 Π) radical. Rotational constants of the complex are reported. The scattering calculations of integral and differential cross sections are performed using both the fully quantum close-coupling (CC) and coupled-states (CS) methods. The collision energies have the values taken from the experiment of Macdonald and Liu (J. Chem. Phys. 1992, 97, 978). The excellent agreement between theoretical and experimental scattering results attests good quality of the ab initio potential.