G0W0 based on time-dependent auxiliary density perturbation theory

G(0)W(0) equations are represented on the space generated by auxiliary functions used for the variational fitting of Coulomb potentials in density functional theory. It is shown that the Coulomb coupling matrix found in auxiliary density perturbation theory is just the discrete representation of the polarization function on the basis of auxiliary functions. In a similar way very compact expressions are found for the dielectric matrix and the screened potential. Additionally, a linearized form of analytic continuation is proposed by importing information from electron propagator methods about the location of Green's function poles. Implementation into the software packages Nagual and deMon2k was performed. Numerical results are presented for a small set of molecules and for the GW100 set, including the use of Hartree-Fock and Kohn-Sham reference states with double and triple zeta basis sets. Accuracy of results demonstrates the reliability of the approach implemented in this work which is the most natural in the context of auxiliary density functional theory.

Automated summary

The study presents G(0)W(0) equations through Coulomb potential fitting and auxiliary density functional theory, leading to compact expressions for Coulomb coupling matrix, dielectric matrix, and screened potential. Additionally, a linearized form of analytic continuation is proposed and implemented in two software packages, showing reliability in numerical results.