title: Analysis of the HO2 vibrational spectrum on an accurate ab initio potential energy surface.
abstract: The complete vibrational spectrum of the HO2(X(2)A' ') radical, up to the H + O2 dissociation limit, has been determined quantum mechanically on an accurate potential energy surface (PES), based on approximately 15000 ab initio points at the icMRCI+Q/aug-cc-pVQZ level of theory. The vibrational states are found to be assignable at low energies but become more irregular as the energy approaches the dissociation limit. However, even at very high energies, regularity still exists, in sharp contrast to earlier results based on the double many-body expansion (DMBE) IV potential. Several Fermi resonances have been identified, and the spectrum is fit with a spectroscopic Hamiltonian. In addition, the vibrational dynamics is analyzed using a periodic orbit approach.
authors.affiliation: Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: Chuanxiu
authors.initials: C
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.forename: Daiqian
authors.initials: D
authors.lastname: Xie
authors.forename: Stavros C
authors.initials: SC
authors.lastname: Farantos
authors.forename: Shi Ying
authors.initials: SY
authors.lastname: Lin
authors.forename: Hua
authors.initials: H
authors.lastname: Guo