Configuration-Interaction study of lower excited states of O2: Valence and rydberg characters of the two lowest 3Σu− states

Configuration-interaction calculations, with an extended basis, are carried out on the ground and lower excited states of O2 and O2+ at and near the equilibrium internuclear distance (R = 2.3 a.u.) of the ground state of O2. Particular attention has been paid to the two lowest 3Σu− states, and the mixing of the valence and Rydberg characters in these states are studied. The lowest 3Σu− state is a Rydberg-type state for R < 2.3 a.u., but becomes valence-type for R ≳ 2.3 a.u. The second 3Σu− state, which is 1.6 eV above the lowest 3Σu− at R = 2.3 a.u., changes its character from Rydberg to valence, valence to Rydberg, and then to valence again when R increases from 1.9 to 3.1 a.u. Satisfactory agreement between the calculated and experimental vertical excitation energies is obtained.

[1]  Bowen Liu,et al.  Abinitio configuration interaction study of the valence states of O2 , 1977 .

[2]  S. Peyerimhoff,et al.  AB initio vibrational analysis of the Schumann—Runge bands and the neighboring absorption region of molecular oxygen , 1976 .

[3]  M. Yoshimine,et al.  The second 3Σ−u state of O2 , 1976 .

[4]  M. Ogawa.  Rotational Analysis of the Absorption Spectrum of Heavy Oxygen (18O2) in the Region 1200–1285 Å , 1975 .

[5]  W. Goddard,et al.  Configuration interaction studies on low‐lying states of O2 , 1975 .

[6]  S. Peyerimhoff,et al.  Ab initio study of the mixing of valence and Rydberg states in O2: CI potential curves for the3Σu−,3Δu and3Πu states , 1975 .

[7]  E. Davidson,et al.  Nonrelativistic configuration interaction calculations for the ground state of the vanadium atom , 1975 .

[8]  R. Celotta,et al.  Apparent Oscillator Strengths for Molecular Oxygen Derived from Electron Energy-Loss Measurements , 1975 .

[9]  S. Peyerimhoff,et al.  Theoretical study of the vertical electronic spectrum of O2: Mixing of valence and Rydberg states , 1975 .

[10]  K. Yamawaki,et al.  Vibrational isotope shifts of absorption bands of 16O2 and 18O2 in the region 1130–1300 Å , 1975 .

[11]  R. S. Mulliken.  Mixed V states , 1974 .

[12]  P. Hay.  On the calculation of natural orbitals by perturbation theory , 1973 .

[13]  A. D. McLean,et al.  Classification of configurations and the determination of interacting and noninteracting spaces in configuration interaction , 1973 .

[14]  S. Peyerimhoff,et al.  Comparison of various CI treatments for the description of potential curves for the lowest three states of O2 , 1972 .

[15]  Paul H. Krupenie.  The Spectrum of Molecular Oxygen , 1972 .

[16]  V. McKoy,et al.  Applicability of SCF Theory to Some Open-Shell States of CO, N2, and O2 , 1971 .

[17]  K. Morokuma,et al.  Diffuse Orbitals in Lower States of the Oxygen Molecule , 1971 .

[18]  Henry F. Schaefer,et al.  Ab Initio Potential Curve for the X 3Σg− State of O2 , 1971 .

[19]  H. Schaefer,et al.  Ab Initio Calculations on 62 Low‐Lying States of the O2 Molecule , 1968 .

[20]  C. Bender.  NATURAL ORBITAL BASED ENERGY CALCULATION FOR HELIUM HYDRIDE AND LITHIUM HYDRIDE , 1966 .

[21]  F. Gilmore.  Potential energy curves for N2, NO, O2 and corresponding ions , 1965 .

[22]  E. Clementi.  Correlation Energy for Atomic Systems , 1963 .

[23]  Frederick Albert Matsen IV,et al.  Perturbation Energy Coefficients and Ionization Potentials of the Ground State of Three- to Ten-Electron Isoelectronic Atomic Series , 1962 .

[24]  Eiichi Ishiguro,et al.  Electronic Structure of Simple Homonuclear Diatomic Molecules II. Lithium Molecule , 1957 .

[25]  W. Moffitt.  The electronic structure of the oxygen molecule , 1951, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[26]  A. C. Wahl,et al.  Hartree-Fock-Roothaan wavefunctions for diatomic molecules: II. First-row homonuclear systems A2, A2±, and A2∗ , 1974 .

[27]  M. Yoshimine,et al.  Configuration-interaction study of atoms. I. Correlation energies of B, C, N, O, F, and Ne , 1974 .