The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial
The equation obtained by mapping the matrix representation of the Schrödinger equation with the 2nd-order correlation transition matrix elements into the 2-body space is the so called correlation contracted Schrödinger equation (CCSE) (Alcoba, Phys Rev A 2002, 65, 032519). As shown by Alcoba (Phys R...
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2009
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00207608_v109_n14_p3178_Alcoba http://hdl.handle.net/20.500.12110/paper_00207608_v109_n14_p3178_Alcoba |
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paper:paper_00207608_v109_n14_p3178_Alcoba2023-06-08T14:41:31Z The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial Anti-hermitian contracted schrödinger equation Contracted schrodinger equation Correlation matrix Electronic correlation effects G-matrix Reduced density matrix Contracted schrodinger equation Correlation matrix Electronic correlation effects G-matrix Reduced density matrix Beryllium Correlation detectors Correlation methods Schrodinger equation Mathematical operators The equation obtained by mapping the matrix representation of the Schrödinger equation with the 2nd-order correlation transition matrix elements into the 2-body space is the so called correlation contracted Schrödinger equation (CCSE) (Alcoba, Phys Rev A 2002, 65, 032519). As shown by Alcoba (Phys Rev A 2002, 65, 032519) the solution of the CCSE coincides with that of the Schrödinger equation. Here the attention is focused in the vanishing hypervirial of the correlation operator (GHV), which can be identified with the anti-Hermitian part of the CCSE. A comparative analysis of the GHV and the anti-Hermitian part of the contracted Schrödinger equation (ACSE) indicates that the former is a stronger stationarity condition than the latter. By applying a Heisenberg-like unitary transformation to the G-particle-hole operator (Valdemoro et al., Phys Rev A 2000, 61, 032507), a good approximation of the expectation value of this operator as well as of the GHV is obtained. The method is illustrated for the case of the Beryllium isoelectronic series as well as for the Li2 and BeH2 molecules. The correlation energies obtained are within 98.80-100.09% of the full-configuration interaction ones. The convergence of these calculations was faster when using the GHV than with the ACSE. © 2009 Wiley Periodicals, Inc. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00207608_v109_n14_p3178_Alcoba http://hdl.handle.net/20.500.12110/paper_00207608_v109_n14_p3178_Alcoba |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Anti-hermitian contracted schrödinger equation Contracted schrodinger equation Correlation matrix Electronic correlation effects G-matrix Reduced density matrix Contracted schrodinger equation Correlation matrix Electronic correlation effects G-matrix Reduced density matrix Beryllium Correlation detectors Correlation methods Schrodinger equation Mathematical operators |
spellingShingle |
Anti-hermitian contracted schrödinger equation Contracted schrodinger equation Correlation matrix Electronic correlation effects G-matrix Reduced density matrix Contracted schrodinger equation Correlation matrix Electronic correlation effects G-matrix Reduced density matrix Beryllium Correlation detectors Correlation methods Schrodinger equation Mathematical operators The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial |
topic_facet |
Anti-hermitian contracted schrödinger equation Contracted schrodinger equation Correlation matrix Electronic correlation effects G-matrix Reduced density matrix Contracted schrodinger equation Correlation matrix Electronic correlation effects G-matrix Reduced density matrix Beryllium Correlation detectors Correlation methods Schrodinger equation Mathematical operators |
description |
The equation obtained by mapping the matrix representation of the Schrödinger equation with the 2nd-order correlation transition matrix elements into the 2-body space is the so called correlation contracted Schrödinger equation (CCSE) (Alcoba, Phys Rev A 2002, 65, 032519). As shown by Alcoba (Phys Rev A 2002, 65, 032519) the solution of the CCSE coincides with that of the Schrödinger equation. Here the attention is focused in the vanishing hypervirial of the correlation operator (GHV), which can be identified with the anti-Hermitian part of the CCSE. A comparative analysis of the GHV and the anti-Hermitian part of the contracted Schrödinger equation (ACSE) indicates that the former is a stronger stationarity condition than the latter. By applying a Heisenberg-like unitary transformation to the G-particle-hole operator (Valdemoro et al., Phys Rev A 2000, 61, 032507), a good approximation of the expectation value of this operator as well as of the GHV is obtained. The method is illustrated for the case of the Beryllium isoelectronic series as well as for the Li2 and BeH2 molecules. The correlation energies obtained are within 98.80-100.09% of the full-configuration interaction ones. The convergence of these calculations was faster when using the GHV than with the ACSE. © 2009 Wiley Periodicals, Inc. |
title |
The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial |
title_short |
The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial |
title_full |
The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial |
title_fullStr |
The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial |
title_full_unstemmed |
The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial |
title_sort |
correlation contracted schrodinger equation: an accurate solution of the g-particle-hole hypervirial |
publishDate |
2009 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00207608_v109_n14_p3178_Alcoba http://hdl.handle.net/20.500.12110/paper_00207608_v109_n14_p3178_Alcoba |
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1768542300926902272 |