Rotational excitation of the interstellar NH2 radical by H2

We present quantum close-coupling calculations for the rotational excitation of the interstellar amidogen radical NH2 due to collisions with H-2 molecules. The calculations are based on a recent, high-accuracy full-dimensional NH4 potential energy surface adapted for rigid-rotor scattering calculations. The collisional cross section calculations are performed for all transitions among the first 15 energy levels of both ortho- and para-NH2 and for total energies up to 1500 cm(-1). Both para- and ortho-H-2 colliding partners are considered. The cross sections for collision with para- and ortho-H-2 are found to differ significantly, the magnitude of the ortho-H-2 ones being dominant. No strong propensity rules are observed but transitions with Delta k(c) = 0 are slightly favored. Published by AIP Publishing.