Rotationally resolved photoionization of molecular oxygen

Journal Article · Wed Apr 15 04:00:00 EDT 1992 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.462671· OSTI ID:7234527

Braunstein, M; McKoy, V ^[1]; Dixit, S N ^[2]

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1. Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States)
2. Theoretical Atomic and Molecular Physics Group, Lawrence Livermore National Laboratory, L-493, Livermore, California 94550 (United States)

We report the results of theoretical studies of the rotationally resolved photoelectron spectra of ground state O{sub 2} leading to the {ital X} {sup 2}{Pi}{sub {ital g}} state of O{sup +}{sub 2} via the absorption of a single vacuum ultraviolet photon. These studies elaborate on a recent report (M. Braunstein {ital et} {ital al}., J. Chem. Phys. {bold 93}, 5345 (1990)) where we showed that a shape resonance near threshold creates a significant dependence of the rotational branching ratios on the ion vibrational level. We also showed that analysis of the rotational branches yields detailed information on the angular momentum composition of the shape resonance. We continue this analysis giving a comprehensive derivation of the rotationally resolved cross sections and photoelectron angular distributions. We discuss the selection rules implied by these expressions and present very high resolution cross sections ({ital J}{r arrow}{ital J}{sup +}) obtained using static-exchange photoelectron orbitals and explicitly taking into account the internuclear distance dependence of the electronic transition moment. These cross sections illustrate the selection rules and show more explicitly the angular momentum composition of the shape resonance. We also present rotationally resolved photoelectron angular distributions which would be expected at low energy.

• DOE Contract Number: FG03-87ER60513; W-7405-ENG-48
• OSTI ID: 7234527
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 96:8; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664100* -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
664200 -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION
ANGULAR MOMENTUM
CROSS SECTIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY
ENERGY DEPENDENCE
ENERGY LEVELS
EXCITED STATES
GROUND STATES
IONIZATION
MOLECULES
NONMETALS
OXYGEN
PHOTOIONIZATION
RADIATIONS
RESOLUTION
RESONANCE ABSORPTION
ROTATIONAL STATES
SELECTION RULES
SORPTION
THRESHOLD ENERGY
ULTRAVIOLET RADIATION
VIBRATIONAL STATES