Ab initio theoretical calculation and potential energy surface for ground-state HO3

The potential energy surface for the HO3→HO+O2 reaction has been studied using the QCISD(T)/CBS (complete basis set) method. The HO3 molecule is found to be stable relative to the HO+O2 dissociation limit. It has a planar equilibrium geometry, with the cis-HO3 structure being slightly more stable than the trans-HO3 one. The classical dissociation barrier height is predicted to be 8.87 kcal mol−1. Based on the calculated energy points, a new double many-body expansion (DMBE II) potential energy surface for HO3 was obtained.