ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The implementation of the density-functional scheme requires the knowledge of the exchange and correlation potential, Vxc, as a functional of the electron density. In the local-density approximation (LDA) this potential becomes a function of the local value of the density. This ansatz breaks down qualitatively at a surface because of its neglect of long-range electron-electron correlations in the presence of strong charge inhomogeneity. This breakdown is of relevance in the context of various surface spectroscopies. We outline a scheme for going beyond the LDA without invoking gradient expansions. This scheme is based on establishing an interrelation between density-functional theory and many-body perturbation theory. In this scheme Vxc is obtainable from the knowledge of the electron self-energy Σxc. We solve an exact integral equation relating these two quantities for the electron-gas surface with use of the GW approximation for the self-energy. We establish a “nonlocal” relation between Vxc and the electron density which allows us to carry out nonlocal density-functional calculations with the same ease as LDA-based calculations. We present results of the first application of our method for the case of Al and Pd surfaces. In addition, we report on work in progress devoted to a detailed comparison of the density-functional and quasiparticle pictures of electronic excitations at a metal surface. © 1992 John Wiley & Sons, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560440873
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