Category:GW: Difference between revisions

Theory

The GW approximation goes hand in hand with the RPA, since the very same diagrammatic contributions are taken into account in the screened Coulomb interaction of a system often denoted as W. However, in contrast to the RPA/ACFDT, the GW method provides access to the spectral properties of the system by means of determining the energies of the quasi-particles of a system using a screened exchange-like contribution to the self-energy. The GW approximation is currently one of the most accurate many-body methods to calculate band-gaps.

More information about the GW method can be found on the following page: GW approximation of Hedin's equations

Practical guides

While more recent versions of VASP (6.0 and newer) support GW calculations in one go, older versions require two steps. First, a groundstate DFT calculation is performed, followed by the actual GW step.

More detailed guides for the GW method are bound below.

How to

• Practical guide to GW calculations.
• Practical guide to GW calculations for large systems.
• Using the GW routines for the determination of frequency-dependent dielectric matrix: GW and dielectric matrix.

Tutorials

• Tutorial for GW calculations.
• Lecture on GW.
• Lecture on the optical bandgap, including in GW.