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.
Titolo: | AB-INITIO CALCULATIONS OF THE QUASI-PARTICLE AND ABSORPTION-SPECTRA OF CLUSTERS - THE SODIUM TETRAMER |
Autori: | ONIDA, GIOVANNI (Primo) |
Settore Scientifico Disciplinare: | Settore FIS/03 - Fisica della Materia Settore CHIM/02 - Chimica Fisica |
Data di pubblicazione: | 1995 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1103/PhysRevLett.75.818 |
Appare nelle tipologie: | 01 - Articolo su periodico |