An accurate many-body expansion potential energy surface for HO2 (X 2A") by extrapolation to the complete basis set limit and quantum dynamics of the related reaction O(3P) + OH(2?)

A new global many-body expansion potential energy surface (PES) for the ground electronic state of HO2 is constructed. All ab initio energy points are employed using aug-cc-pV(Q+ d)Z and aug-cc-pV(5+ d)Z basis sets at the multi-reference conformational interaction level and then extrapolated to the complete basis set limit. The topographic characteristics of the global PES for HO2 (X (2)A") are discussed in detail and compared with experimental results, showing good agreement. We subsequently consider the O(P-3) + OH((2)?) ?O-2((3) S-g- 2S) reaction using the time-dependent wave packet method and calculate dynamics behaviors, including the vibration-rotation distribution and reaction probabilities. The results indicate that the new PES is suitable for dynamics investigations of O(P-3) + OH((2)?) ? O-2((3) S-g- ) + H(S-2) and can be used as a component for PESs to construct larger oxygen/hydrogen containing systems.