Fully ab initio investigation of bound and predissociating states of the NeOH( X ) complex

New ab initio potential energy surfaces (PESs) are reported for the interaction of Ne(1S0) with the OH radical in its ground (X 2Π) electronic state. These are then used in the variational calculation of the bound vibrational states of the NeOH(X) complex. The calculated dissociation energy (D0) is 26.2 cm−1, which lies within the experimental estimate (23–30 cm−1). The ab initio PESs are also used to determine the positions and widths of the metastable levels of the complex which correlate with the first excited rotational state (j=5/2, ω=3/2) and the first excited spin–orbit state (j=1/2, ω=1/2) of OH(X 2Π). The predissociation rates are strongly dependent on the bending motion, the intermolecular stretching vibrational quantum number and the parity. The predissociation lifetimes are in good agreement with estimates from stimulated emission pumping experiments of [Chuang, Andrews, and Lester, J. Chem. Phys. 103, 3418 (1995)]. A quantum flux method is used to study the redistribution of the predissociation flux as a function of the fragment separation.