Zero-point Renormalization of the Band Gap of Semiconductors and Insulators Using the PAW Method

Description

We evaluate the zero-point renormalization (ZPR) due to electron-phonon interactions of 28 solids using the projector-augmented-wave (PAW) method. Particular care is taken to include long-range electrostatic interactions via a generalized Fröhlich model. We discuss the evaluation of the electron-phonon matrix elements within the PAW method. Two distinct versions can be obtained depending on when the atomic derivatives are taken. If the PAW transformation is applied before taking the derivatives, equations similar to the ones conventionally used in pseudopotential codes are obtained. If the PAW transformation is used after taking the derivatives, the full-potential spirit is largely maintained. We show that both variants yield very similar ZPRs for selected materials when the rigid-ion approximation is employed. In practice, we find that the pseudo version converges more rapidly with respect to the number of included unoccupied states.

Period	22 Aug 2022 → 25 Aug 2022
Event title	Psi-k Conference 2022
Event type	Conference
Location	Lausanne, SwitzerlandShow on map
Degree of Recognition	International