@article{386, keywords = {clusters, electron states, spectroscopy, Ab initio calculations, paper}, author = {Lucia Reining and G Onida and Stefan Albrecht}, title = {First-principles approach to the calculation of electronic spectra in clusters}, abstract = {We discuss a method for first-principles calculations of photoemission spectra in small clusters, going well beyond a standard density functional theory-local density approximation (DFT-LDA) approach. Starting with a DFT-LDA calculation, we evaluate self-energy contributions to the quasiparticle energies of an electron or hole in the GW scheme, where the self-energy Sigma = GW is constructed from the one-particle Green\textquoterights function G and the RPA screened Coulomb interaction W. The contributions of structural relaxation are taken into account. We show the importance of these effects at the example of the photoemission spectrum of SiH4. We also briefly discuss results for longer hydrogenated silicon chains, and address the problem of optical absorption. Copyright (C) 1998 Elsevier Science B.V.}, year = {1998}, journal = {Comp. Mat. Science}, volume = {10}, number = {1-4}, pages = {444-447}, month = {FEB}, publisher = {European Mat Res Soc}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, note = {Symposium on Computational Modeling of Issues in Materials Science at the International Conference on Applied Materials / European-Materials-Research-Society Meeting, STRASBOURG, FRANCE, JUN 16-20, 1997}, }