@article{389,
  keywords = {paper},
  author = {G Onida and Lucia Reining and RW Godby and Rodolfo Del Sole and W ANDREONI},
  title = {Ab-initio calculations of the quasi-particule and absorption spectra of clusters: the sodium tetramer},
  abstract = {We report the first ab initio quasiparticle calculation in a real cluster Na-4 within Hedin\textquoterights 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.},
  year = {1995},
  journal = {Phys. Rev. Lett.},
  volume = {75},
  number = {5},
  pages = {818-821},
  month = {JUL 31},
  publisher = {AMERICAN PHYSICAL SOC},
  address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA},
}