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Title: Molecular resonance phenomena. [Calculation of resonance widths]

Abstract

It is attempted to show that the Stieltjes-moment-theory provides a practical and a reasonably accurate method for calculating the widths of molecular resonances. The method seems to possess a number of advantages for molecular applications, since it avoids the explicit construction of continuum wavefunctions. It is very simple to implement the technique numerically, because it requires only existing bound-state electronic structure codes. Through the use of configuration interaction techniques, many-electron correlation and polarization effects can be included in the description of both the resonance and the non-resonant background continuum. To illustrate the utility and the accuracy of the Stieltjes-moment-theory technique, used in conjunction with configuration interaction (CI) wave functions, recent applications to the /sup 1/..sigma../sub u/(1sigma/sub u/ 2sigma/sub g/) autoionizing resonance state of H/sub 2/ and the well known /sup 2/PI/sub g/ state of N/sub 2//sup -/ are discussed. The choices of the one-electron basis sets and the types of many-electron configurations appropriate for these two cases are described. Also, guidelines for the selection of the projection operators defining the resonant and non-resonant subspaces in the case of both Feshbach and shape-resonances are given. The numerical results indicate that the Stieltjes-moment-theory technique, which employs L/sup 2/ basis functions exclusively, producesmore » as accurate resonance parameters as can be extracted from direct electron-molecule scattering calculations, provided approximately the same approximations are used to describe important physical effects such as target polarization. Furthermore the method provides sufficiently accurate fixed-nuclei electronic resonance parameters to be used in ab initio calculation of resonant vibrational excitation cross sections. (WHK)« less

Authors:
Publication Date:
Research Org.:
Lawrence Livermore National Lab., CA (USA)
OSTI Identifier:
6498816
Report Number(s):
UCRL-85858; CONF-8005162-1
TRN: 81-010879
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Conference
Resource Relation:
Conference: Workshop on electron-atom and electron-molecule collisions, Bielefeld, F.R. Germany, 5 May 1980
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; HYDROGEN; EXCITED STATES; MOLECULES; NITROGEN; AUTOIONIZATION; CALCULATION METHODS; ELECTRON-MOLECULE COLLISIONS; ELECTRONIC STRUCTURE; LINE WIDTHS; POLARIZATION; RESONANCE; WAVE FUNCTIONS; COLLISIONS; ELECTRON COLLISIONS; ELEMENTS; ENERGY LEVELS; FUNCTIONS; IONIZATION; MOLECULE COLLISIONS; NONMETALS; 640305* - Atomic, Molecular & Chemical Physics- Atomic & Molecular Theory- (-1987)

Citation Formats

Hazi, A U. Molecular resonance phenomena. [Calculation of resonance widths]. United States: N. p., 1980. Web.
Hazi, A U. Molecular resonance phenomena. [Calculation of resonance widths]. United States.
Hazi, A U. 1980. "Molecular resonance phenomena. [Calculation of resonance widths]". United States. https://www.osti.gov/servlets/purl/6498816.
@article{osti_6498816,
title = {Molecular resonance phenomena. [Calculation of resonance widths]},
author = {Hazi, A U},
abstractNote = {It is attempted to show that the Stieltjes-moment-theory provides a practical and a reasonably accurate method for calculating the widths of molecular resonances. The method seems to possess a number of advantages for molecular applications, since it avoids the explicit construction of continuum wavefunctions. It is very simple to implement the technique numerically, because it requires only existing bound-state electronic structure codes. Through the use of configuration interaction techniques, many-electron correlation and polarization effects can be included in the description of both the resonance and the non-resonant background continuum. To illustrate the utility and the accuracy of the Stieltjes-moment-theory technique, used in conjunction with configuration interaction (CI) wave functions, recent applications to the /sup 1/..sigma../sub u/(1sigma/sub u/ 2sigma/sub g/) autoionizing resonance state of H/sub 2/ and the well known /sup 2/PI/sub g/ state of N/sub 2//sup -/ are discussed. The choices of the one-electron basis sets and the types of many-electron configurations appropriate for these two cases are described. Also, guidelines for the selection of the projection operators defining the resonant and non-resonant subspaces in the case of both Feshbach and shape-resonances are given. The numerical results indicate that the Stieltjes-moment-theory technique, which employs L/sup 2/ basis functions exclusively, produces as accurate resonance parameters as can be extracted from direct electron-molecule scattering calculations, provided approximately the same approximations are used to describe important physical effects such as target polarization. Furthermore the method provides sufficiently accurate fixed-nuclei electronic resonance parameters to be used in ab initio calculation of resonant vibrational excitation cross sections. (WHK)},
doi = {},
url = {https://www.osti.gov/biblio/6498816}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1980},
month = {Tue Jan 01 00:00:00 EST 1980}
}

Conference:
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