Electron correlation in chemical bonds

Vitaly A. Rassolov, Mark A Ratner, John A. Pople

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

We study the correlation energy in the H2 molecule as a function of bond distance and the electron coupling parameter that modifies the strength of electron-electron repulsion. For the unscaled electron repulsion we find an unusual complexity of the correlation energy dependence on the bond distance. This complexity remains if the electron repulsion is scaled down. We pay particular attention to the range of bond distances near the H2 equilibrium geometry. We confirm that good performance of the modern exchange-correlation functionals in molecular geometry optimization is due to the cancellation of errors between the exchange and correlation components. These components have different functional dependence on the electron coupling parameter, so the cancellation of errors no longer occurs when the electron repulsion is scaled down. This observation is important if the adiabatic connection theorem is used to construct the exchange-correlation functionals. It is also relevant for the performance of exchange-correlation functionals to study ionic interactions. The performance of the correlation operator in the molecular environment is also investigated and discussed.

Original languageEnglish
Pages (from-to)4014-4019
Number of pages6
JournalJournal of Chemical Physics
Volume112
Issue number9
Publication statusPublished - Mar 1 2000

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Electron correlations
Chemical bonds
chemical bonds
Electrons
functionals
electrons
cancellation
Geometry
geometry
theorems
operators
Molecules
optimization
energy

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Rassolov, V. A., Ratner, M. A., & Pople, J. A. (2000). Electron correlation in chemical bonds. Journal of Chemical Physics, 112(9), 4014-4019.

Electron correlation in chemical bonds. / Rassolov, Vitaly A.; Ratner, Mark A; Pople, John A.

In: Journal of Chemical Physics, Vol. 112, No. 9, 01.03.2000, p. 4014-4019.

Research output: Contribution to journalArticle

Rassolov, VA, Ratner, MA & Pople, JA 2000, 'Electron correlation in chemical bonds', Journal of Chemical Physics, vol. 112, no. 9, pp. 4014-4019.
Rassolov VA, Ratner MA, Pople JA. Electron correlation in chemical bonds. Journal of Chemical Physics. 2000 Mar 1;112(9):4014-4019.
Rassolov, Vitaly A. ; Ratner, Mark A ; Pople, John A. / Electron correlation in chemical bonds. In: Journal of Chemical Physics. 2000 ; Vol. 112, No. 9. pp. 4014-4019.
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