First-principles approach to the calculation of electronic spectra in clusters
|Title||First-principles approach to the calculation of electronic spectra in clusters|
|Publication Type||Palaiseau Article|
|Author Address|| |
Reining, L (Reprint Author), Ecole Polytech, Solides Irradies Lab, CEA, CNRS, F-91128 Palaiseau, France. Ecole Polytech, Solides Irradies Lab, CEA, CNRS, F-91128 Palaiseau, France. Univ Roma Tor Vergata, Dipartimento Fis, Ist Nazl Fis Mat, I-00133 Rome, Italy.
|Reining, L, Onida, G, Albrecht, S|
|Year of Publication||1998|
|Journal||Comp. Mat. Science|
|Keywords||clusters; electron states; spectroscopy; ab initio calculations, paper|
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's 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.