Schindlmayr, A, Garcia-Gonzalez, P and Godby, R W (2001) Diagrammatic self-energy approximations and the total particle number. Physical review b. 235106. -. ISSN 1098-0121Full text available as:
There is increasing interest in many-body perturbation theory as a practical tool for the calculation of ground-state properties. As a consequence, unambiguous sum rules such as the conservation of particle number under the influence of the Coulomb interaction have acquired an importance that did not exist for calculations of excited-state properties. In this paper we obtain a rigorous, simple relation whose fulfilment guarantees particle-number conservation in a given diagrammatic self-energy approximation. Hedin's G(0)W(0) approximation does not satisfy this relation and hence violates the particle-number sum rule. Very precise calculations for the homogeneous electron gas and a model inhomogeneous electron system allow the extent of the nonconservation to be estimated.
|Copyright, Publisher and Additional Information:||© 2001 American Physical Society. Published in Physical Review B and uploaded in accordance with the publisher's self archiving policy.|
|Keywords:||SPACE-TIME METHOD, ELECTRON-GAS, SPECTRAL FUNCTIONS, GW APPROXIMATION, BAND-GAPS, SEMICONDUCTORS, SURFACE, DENSITY, CONSERVATION, INSULATORS|
|Academic Units:||The University of York > Physics (York)|
|Depositing User:||Physics Import|
|Date Deposited:||17 Sep 2008 17:33|
|Last Modified:||17 Oct 2013 14:34|