Ab initio calculation of the quasiparticle spectrum and excitonic effects in Li2O
|Title||Ab initio calculation of the quasiparticle spectrum and excitonic effects in Li2O|
|Publication Type||Palaiseau Article|
|Author Address|| |
Albrecht, S (Reprint Author), ECOLE POLYTECH,CEREM,CEA,URA 1380 CNRS,LAB SOLIDES IRRADIES,F-91128 PALAISEAU,FRANCE. UNIV ROMA TOR VERGATA,DIPARTIMENTO FIS,IST NAZL FIS MAT,I-00133 ROME,ITALY.
|Albrecht, S, Onida, G, Reining, L|
|Year of Publication||1997|
|Journal||Phys. Rev. B|
We report an ab initio calculation of the binding energies and the nature of the excitonic states in the near-gap absorption spectrum of a real solid, Li2O. We calculate the ground-state properties using density-functional theory together with soft pseudopotentials. Applying Hedin's GW approximation for the self-energy corrections to the band structure, we determine the minimal gap about 1 eV above the measured absorption onset. Finally, we obtain agreement with experiment by solving an effective two-particle Schrodinger equation for the electron-hole pairs.