Beyond the random phase approximation with a local exchange vertex

Abstract

With the aim of constructing an electronic structure approach that systematically goes beyond the GW and random phase approximation (RPA) we introduce a vertex correction based on the exactexchange (EXX) potential of time-dependent density functional theory. The EXX vertex function is constrained to be local but is expected to capture similar physics as the Hartree-Fock vertex. With the EXX vertex we then consistently unify different beyond-RPA approaches such as the various re-summations of RPA with exchange (RPAx) and the second order screened exchange (SOSEX) approximation. The theoretical analysis is supported by numerical studies on the hydrogen dimer and the electron gas, and we discuss the importance of including the vertex correction in both the screened interaction and the self energy. Finally, we give details on our implementation within the plane-wave pseudo potential framework and demonstrate the excellent performance of the different RPAx methods in describing the energetics of hydrogen and van der Waals bonds.

Stochastic Vertex Corrections: Linear Scaling Methods for Accurate Quasiparticle Energies

“…This observation is consistent with previous theoretical results based on local vertex corrections that incorporate derivative discontinuity. 41,42 Here such discontinuity is included via the time-dependent induced exchange potential W x in the G 0 W tc 0 Γ X self-energy (Eq. 37).…”

Range-separated double-hybrid density-functional theory with coupled-cluster and random-phase approximations

“…We test now the RS2H+CCD and RS2H+RPAxSO2 methods on weak intermolecular interactions. Table III reports the interaction energies for the 24 complexes of the A24 set calculated by RSH+CCD, RS2H+CCD, CCD, RSH+RPAxSO2, RS2H+RPAxSO2, and [66].…”

Efficient Kr/Xe separation from triangular g-C3N4 nanopores, a simulation study

“…The EXX/RPA method has been proved to correctly capture vdW correlations, 58,59 and e.g., the results of physisorption binding energies between different types of molecules and surfaces show an excellent agreement with the values measured by experiments. [60][61][62][63][64][65][66] The RPA/EXX results reveal that the Grimme-D2, Grimme-D3 and TS approximations yield a good agreement PES (Fig. 4).…”