First-principles calculations for the tunnel ionization rate of atoms and molecules

Journal Article · Sat May 01 04:00:00 EDT 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.69.053404· OSTI ID:20643636

Otobe, T; Yabana, K; Iwata, J -I ^[1]

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1. Institute of Physics, University of Tsukuba, Tsukuba 305-8571 (Japan)

We present first-principles calculations for the tunnel ionization rate of some atoms and molecules in a static intense electric field. The Gamow state is calculated to describe the ionization process in the Kohn-Sham formalism with the self-interaction correction. The tunnel ionization rate is obtained from the imaginary part of the Gamow state eigenvalue. The ionization rates of rare-gas atoms Ar and Xe and diatomic molecules N{sub 2}, O{sub 2}, and F{sub 2} are investigated. The calculations describe well the observed behavior of the tunnel ionization. The results also show good correspondence with the Ammosov-Delone-Krainov model for rare-gas atoms. We find that the properties of the highest occupied orbital have significant effects on the ionization rate. In particular, our calculation reproduces the suppression of the ionization rate of O{sub 2} molecule in comparison with that of Xe atom. We also find that the ionization rates of O{sub 2} and F{sub 2} molecules are very sensitive to the relative angle between the electric field and the molecular axis, reflecting properties of the highest occupied orbital.

• OSTI ID: 20643636
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 69; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOMS
COMPARATIVE EVALUATIONS
CORRECTIONS
EIGENFUNCTIONS
EIGENVALUES
ELECTRIC FIELDS
FLUORINE
MOLECULES
NITROGEN
OXYGEN
PHOTOIONIZATION
PHOTON-ATOM COLLISIONS
PHOTON-MOLECULE COLLISIONS
XENON