Global Potential Energy Surface, Vibrational Spectrum, and Reaction Dynamics of the First Excited (Ấ²A′) State of HO₂

Abstract

The authors report extensive high-level ab initio studies of the first excited (Ã A2 ') state of HO2. A global potential energy surface (PES) was developed by spline-fitting 17 000 ab initio points at the internal contracted multireference configuration interaction (icMRCI) level with the AVQZ basis set. To ascertain the spectroscopic accuracy of the PES, the near-equilibrium region of the molecule was also investigated using three interpolating moving least-squares-based PESs employing dynamically weighted icMRCI methods in the complete basis set limit. Vibrational energy levels on all four surfaces agree well with each other and a new assignment of some vibrational features is proposed. In addition, the dynamics of both the forward and reverse directions of the H+ O2 (ã Δ1g) OH+O reaction (J=0) were studied using an exact wave packet method. The reactions are found to be dominated by sharp resonances.

Department(s)

Chemistry

Keywords and Phrases

Ab initio; Ab initio study; Basis sets; Complete basis set limit; Global potential energy surfaces; Moving least squares; Multi reference configuration interactions; Reaction dynamics; Vibrational energy levels; Vibrational features; Wave-packet method, Potential energy; Potential energy surfaces; Quantum chemistry; Sulfur compounds; Excited states

International Standard Serial Number (ISSN)

0021-9606

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2010 American Institute of Physics (AIP), All rights reserved.

Publication Date

01 Oct 2010

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