Figure 24.

Schematic of Hedin's full set of equations (A) and Hedin's GW approximation (B–D). In (A), all five quantities are iterated to self-consistency. In (B), self-consistent GW (scGW), Γ is set to a single spacetime point and the remaining four quantities are determined self-consistently. Eigenvalue self-consistent GW shown in (C), evGW, updates only the quasiparticle energies while leaving the wave functions unchanged. In the scGW₀ or evGW₀ procedures shown in (D), one iterates G to self-consistency in Dyson's equation but does not update χ₀ or W.