We report the first ab initio quasiparticle calculation in a real cluster Na-4 within Hedin's GW approximation for the valence electron self-energy. Our approach avoids the summations over empty states, and also eliminates the problem of residual interactions between the periodic images. Self-energy corrections open the local density approximation gap by more than 2 eV; finite-size effects on screening are shown to play an important role. The absorption spectrum calculated by including excitonic effects using our ab initio screened interaction gives a good account of the experimental photodepletion data.
AB-INITIO CALCULATIONS OF THE QUASI-PARTICLE AND ABSORPTION-SPECTRA OF CLUSTERS - THE SODIUM TETRAMER / G. ONIDA, L. REINING, R. GODBY, R. DELSOLE, W. ANDREONI. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 75:5(1995), pp. 818-821. [10.1103/PhysRevLett.75.818]
AB-INITIO CALCULATIONS OF THE QUASI-PARTICLE AND ABSORPTION-SPECTRA OF CLUSTERS - THE SODIUM TETRAMER
G. OnidaPrimo
;
1995
Abstract
We report the first ab initio quasiparticle calculation in a real cluster Na-4 within Hedin's GW approximation for the valence electron self-energy. Our approach avoids the summations over empty states, and also eliminates the problem of residual interactions between the periodic images. Self-energy corrections open the local density approximation gap by more than 2 eV; finite-size effects on screening are shown to play an important role. The absorption spectrum calculated by including excitonic effects using our ab initio screened interaction gives a good account of the experimental photodepletion data.Pubblicazioni consigliate
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