Study of the predissociation of NH3 in the 3sA"2 state from ab initio UHF calculations

Predissociation of the A"2 state in NH3 is investigated from ab initio UHF calculations of the relevant cross section of the potential energy surface. Emphasis is placed on dissociation products and the role of the Rydberg 3s orbital. The force constants, Rydberg ionisation limit, dissociation barrier and dissociation products are systematically calculated and comparison with experiment is made. A critical examination of a previous hypothesis concerning the predissociation is made and some new aspects are obtained.