Molecular effects on inner-shell photoabsorption. K-shell spectrum of N₂

Journal Article · Thu Jan 01 00:00:00 EST 1976 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.433034· OSTI ID:7329933

Dehmer, Joseph L. ^[1]; Dill, Dan ^[2]

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1. Argonne National Laboratory (ANL), Argonne, IL (United States)
2. Boston Univ., MA (United States). Dept. of Chemistry

K-shell photoabsorption spectra of the first-row diatomic molecules N₂, CO, and NO are known to depart drastically from the behavior characteristic of K-shell excitation in atoms. Below the K-shell thresholds these spectra are dominated by a single, very intense peak rather than normal Rydberg structure, and the first 10--20 eV of the continuum exhibit a broad band of enhanced absorption, rather than a monotonic decrease. We use the multiple-scattering model to compute the discrete part and the first 100 Ry of the photoionization continuum for K-shell photoionization of N₂. This calculation accounts for both novel features described above and shows that they arise from centrifugal barrier effects manifested as shape resonances in high-l components of the final state wavefunctions. These effects are molecular in origin, resulting from the interaction between the photoelectron and the anisotropic molecular field. We also discuss the energy dependence of the photoelectron angular distributions, Kronig structure in the high-energy continuum, bearing of the present results on valence-shell spectra, and the likelihood of widespread observation of shape resonances in ionization processes in other molecules. (AIP)

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: US Energy Research and Development Administration (ERDA)
• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 7329933
• Journal Information: Journal of Chemical Physics, Vol. 65, Issue 12; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CARBON MONOXIDE
ABSORPTION SPECTRA
PHOTOIONIZATION
NITROGEN
NITROGEN OXIDES
EXCITATION
MULTIPLE SCATTERING
PHOTOELECTRIC EFFECT
X-RAY SPECTRA
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CRYOGENIC FLUIDS
ELEMENTS
ENERGY-LEVEL TRANSITIONS
FLUIDS
IONIZATION
NITROGEN COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
SCATTERING
SPECTRA
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena