Theoretical studies of the structure and thermochemistry of FO2 radical: Comparison of Møller-Plesset perturbation, complete-active-space self-consistent-field, and quadratic configuration interaction methods

J. S. Francisco, Y. Zhao, W. A. Lester, I. H. Williams

Research output: Contribution to journalReview article


The structure of FO2 has been calculated for the X 2A″; ground state using Møller-Plesset (MP) perturbation, complete-active-space self-consistent-field (CASSCF), and quadratic configuration interaction (QCI) ab initio molecular orbital methods. Basis sets with polarization and diffuse functions were used. Compared with the experimental structure, bond lengths obtained with MP perturbation methods are found to be consistently too short. CASSCF calculations yield a structure which varies considerably with the size of the active space and basis set used. Calculations using the single-configuration-based QCI in the single and double-space with perturbative inclusion of triple substitutions, denoted by QCISD (T), yield structures very close to the experimental structure of FO 2. The thermochemistry of FO2 radical has been calculated using the MP, QCI, and GAUSSIAN-1 (G1) methods. The QCI method using isodesmic and isogyric schemes has predicted the heat of formation for FO2 at 0 K to be 8.9±3 kcal mol-1.

Original languageEnglish
Pages (from-to)2861-2867
Number of pages7
JournalThe Journal of Chemical Physics
Issue number4
Publication statusPublished - 1 Jan 1992

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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