HUA-GEN YU, Department of Chemistry, Brookhaven National Laboratory, Upton, NY 11973-5000; BASTIAAN J. BRAAMS, Department of Mathematics and Computer Science, Emory University, Atlanta, Georgia 30322.
We have explored the ground-state potential energy surface for HO3 using the HCTH/aug-cc-pVTZ DFT method. Results show that there are two stable isomers, trans-HO3 and cis-HO3, with respect to the OH + O2 dissociation limit. The binding energies are predicted to be 6.68 kcal/mole (D0) for trans-HO3 and 5.62 kcal/mole for cis-HO3. The isomerisation barrier height is only 2.02 kcal/mole from the trans- isomer to the cis- one. The central O-O bond length is obtained as 1.6299 Å in trans-HO3 or 1.5958 Å in cis-HO3. A global potential energy surface has been constructed from thousands of ab initio energy points. Based on this surface, we have carried out a full dimensional quantum dynamics study. Results are used to compare with the FTIR experimental observations.