Questaal Home
Navigation
Questaal News

A hands-on course highlighting Questaal's GW/DMFT/BSE capability. This is an opportunity for researchers to learn about advanced electronic structure and how to use the Questaal Suite.

Questaal News

The Lambrecht group at Case Western University estimated how phonons modify the band structure in SrTiO3. Isolating the Frolich part of the electron-phonon interaction (which is the dominant contribution for highly polar compounds), they estimated the reduction in the screened coulomb interaction W, and its effect on the QSGW band structure.

Ladder Diagrams in QSGW

December 5, 2017 | ARTICLE · QSGW · BSE · LADDER

Questaal News

Recently, Brian Cunningham and Myrta Gruening incorporated ladder diagrams as an extension to the RPA polarizability. Ladder diagrams significantly improve agreement with experimental dielectric response functions. The QSGW framework makes it possible to address systems whose electronic structure is poorly described within the standard perturbative GW approaches with as a starting point density-functional theory calculations. The Figure shows the real and imaginary parts of the dielectric function for Ge.

Questaal News

Metal-organic perovskite solar cells, CH3NH3PbI3 (MAPI) in particular, have attracted much attention recently because of their high power conversion efficiency and potential low cost.

Questaal News

Density-Functional theory, while being immensely popular thanks to its simplicity, nevertheless is limited in its reliability. The QuasiParticle Self-Consistent GW approximation, while more demanding than DFT, is vastly more reliable than DFT, or GW theory based on DFT, for calculation of optical properties in weakly correlated systems.