A comparison of ground-state averages in electron propagator theory
Article first published online: 19 OCT 2004
Copyright © 1993 John Wiley & Sons, Inc.
International Journal of Quantum Chemistry
Supplement: Proceedings of the International Syposium on Atomic, Molecular, and Condensed Matter Theory and Computational Methods
Volume 48, Issue Supplement 27, pages 407–418, 13/20 March 1993
How to Cite
Ortiz, J. V. (1993), A comparison of ground-state averages in electron propagator theory. Int. J. Quantum Chem., 48: 407–418. doi: 10.1002/qua.560480841
- Issue published online: 19 OCT 2004
- Article first published online: 19 OCT 2004
- Manuscript Received: 13 MAR 1993
In the Dyson equation, the self-energy describes all relaxation and correlation corrections to Koopmans's theorem. Energy-independent contributions to the self-energy depend on the one-electron reduced density matrix of the reference state. Three formalisms for calculating these terms are considered: perturbation theory, coupled-cluster theory, and contour integral theory. In one method, combinations of coupled-cluster singles and doubles amplitudes are substituted for first-order double excitation coefficients and for second-order single excitation coefficients. Another approach generates a description of reference state correlation through the evaluation of approximate contour integral expressions. Calculations on electron binding energies of closed-shell molecules and anions reveal that the coupled-cluster results for the energy-independent self-energy terms are closer to the perturbative results than to the contour integral values. © 1993 John Wiley & Sons, Inc.