Renormalized Singles Green's Function in the T-Matrix Approximation for Accurate Quasiparticle Energy Calculation.

ABSTRACT: We combine the renormalized singles (RS) Green's function with the T-matrix approximation for the single-particle Green's function to compute quasiparticle energies for valence and core states of molecular systems. The G_RST₀ method uses the RS Green's function that incorporates singles contributions as the initial Green's function. The G_RST_RS method further calculates the generalized effective interaction with the RS Green's function by using RS eigenvalues in the T-matrix calculation through the particle-particle random phase approximation. The G_RST_RS method provides significant improvements over one-shot methods G₀T₀ and G₀W₀ as demonstrated in calculations for GW100 and CORE65 test sets. It also systematically eliminates the dependence of G₀T₀ on the choice of density functional approximations. For valence states, the G_RST_RS method provides excellent accuracy, which is better than that of G₀T₀ and G₀W₀. For core states, the G_RST_RS method identifies correct peaks in the spectral function and significantly outperforms G₀T₀ on core-level binding energies (CLBEs) and relative CLBEs.

SUBMITTER: Li J 

PROVIDER: S-EPMC8341309 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature