Configurationinteraction relativisticmanybodyperturbationtheory calculations of photoionization cross sections from quasicontinuum oscillator strengths
Abstract
Many applications are in need of accurate photoionization cross sections, especially in the case of complex atoms. Configurationinteraction relativisticmanybodyperturbation theory (CIRMBPT) has been successful in predicting atomic energies, matrix elements between discrete states, and other properties, which is quite promising, but it has not been applied to photoionization problems owing to extra complications arising from continuum states. In this paper a method that will allow the conversion of discrete CI(R)MPBT oscillator strengths (OS) to photoionization cross sections with minimal modifications of the codes is introduced and CIRMBPT cross sections of Ne, Ar, Kr, and Xe are calculated. A consistent agreement with experiment is found. RMBPT corrections are particularly significant for Ar, Kr, and Xe and improve agreement with experimental results compared to the particlehole CI method. As a result, the demonstrated conversion method can be applied to CIRMBPT photoionization calculations for a large number of multivalence atoms and ions.
 Authors:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 New Mexico Consortium, Los Alamos, NM (United States)
 Publication Date:
 Research Org.:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 1234448
 Alternate Identifier(s):
 OSTI ID: 1181057
 Report Number(s):
 LAUR1427819
Journal ID: ISSN 10502947; PLRAAN; TRN: US1600380
 Grant/Contract Number:
 AC5206NA25396
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Physical Review. A
 Additional Journal Information:
 Journal Volume: 90; Journal Issue: 6; Journal ID: ISSN 10502947
 Publisher:
 American Physical Society (APS)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 74 ATOMIC AND MOLECULAR PHYSICS
Citation Formats
Savukov, I. M., and Filin, D. V.. Configurationinteraction relativisticmanybodyperturbationtheory calculations of photoionization cross sections from quasicontinuum oscillator strengths. United States: N. p., 2014.
Web. doi:10.1103/PhysRevA.90.063428.
Savukov, I. M., & Filin, D. V.. Configurationinteraction relativisticmanybodyperturbationtheory calculations of photoionization cross sections from quasicontinuum oscillator strengths. United States. doi:10.1103/PhysRevA.90.063428.
Savukov, I. M., and Filin, D. V.. 2014.
"Configurationinteraction relativisticmanybodyperturbationtheory calculations of photoionization cross sections from quasicontinuum oscillator strengths". United States.
doi:10.1103/PhysRevA.90.063428. https://www.osti.gov/servlets/purl/1234448.
@article{osti_1234448,
title = {Configurationinteraction relativisticmanybodyperturbationtheory calculations of photoionization cross sections from quasicontinuum oscillator strengths},
author = {Savukov, I. M. and Filin, D. V.},
abstractNote = {Many applications are in need of accurate photoionization cross sections, especially in the case of complex atoms. Configurationinteraction relativisticmanybodyperturbation theory (CIRMBPT) has been successful in predicting atomic energies, matrix elements between discrete states, and other properties, which is quite promising, but it has not been applied to photoionization problems owing to extra complications arising from continuum states. In this paper a method that will allow the conversion of discrete CI(R)MPBT oscillator strengths (OS) to photoionization cross sections with minimal modifications of the codes is introduced and CIRMBPT cross sections of Ne, Ar, Kr, and Xe are calculated. A consistent agreement with experiment is found. RMBPT corrections are particularly significant for Ar, Kr, and Xe and improve agreement with experimental results compared to the particlehole CI method. As a result, the demonstrated conversion method can be applied to CIRMBPT photoionization calculations for a large number of multivalence atoms and ions.},
doi = {10.1103/PhysRevA.90.063428},
journal = {Physical Review. A},
number = 6,
volume = 90,
place = {United States},
year = 2014,
month =
}
Web of Science

Quasicontinuum relativistic manybody perturbation theory photoionization cross sections of Na, K, Rb, and Cs
Calculations of photoionization cross sections for alkalimetal atoms are carried out in the framework of relativistic manybody perturbation theory (RMBPT) using quasicontinuum Bspline orbitals. All thirdorder terms are included, in contrast to previous calculations based on either randomphase approximation (RPA), Brueckner orbitals, or their combination. The particular advantage of quasicontinuum states is that highorder MBPT codes do not require modification for applications to the photoionization problem. The agreement with experiment is improved compared to RPA and DiracHartreeFock approximations. The results also exhibit close form invariance. The presented formalism can be extended to other photoionizing transitions. 
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