Abstract
We solve the Dyson equation for the one-particle Green's function in a periodic solid self-consistently within the shielded-interaction (or ) approximation. The effect of self-consistency (propagator renormalization) is found to be substantial. We illustrate this finding via calculations of quasiparticle states in K and Si. In the case of Si we show that the current standard of ab initio quasiparticle theory, the self-energy diagram, fails to account for the observed value of the absolute band gap—if properly, i.e., self-consistently, evaluated.
- Received 18 May 1998
DOI:https://doi.org/10.1103/PhysRevLett.81.1662
©1998 American Physical Society