Advantageous nearsightedness of many-body perturbation theory contrasted with Kohn-Sham density functional theory

For properties of interacting electron systems, Kohn-Sham (KS) theory is often favored over many-body perturbation theory (MBPT), owing to its low computational cost. However, the exact KS potential can be challenging to approximate, for example in the presence of localized subsystems where the exact potential is known to exhibit pathological features such as spatial steps. By modeling two electrons, each localized in a distinct potential well, we illustrate that the step feature has no counterpart in MBPTs (including Hartree-Fock and GW) or hybrid methods involving Fock exchange because the spatial nonlocality of the self-energy renders such pathological behavior unnecessary. We present a quantitative illustration of the orbital-dependent nature of the nonlocal potential, and a numerical demonstration of Kohn's concept of the nearsightedness for self-energies, when two distant subsystems are combined, in contrast to the KS potential. These properties emphasize the value of self-energy-based approximations in developing future approaches within KS-like theories

Data supporting "Insights from exact exchange-correlation kernels"

This is data associated with the publication "Insights from exact exchange-correlation kernels". Three systems are studied. The plots and plotting scripts for each system are contained within the relevant directories. The code and scripts used to generate the data are included within the "code" directory

Data supporting "Accurate Total Energies from the Adiabatic-Connection Fluctuation-Dissipation Theorem"

This is data associated with the publication "Accurate Total Energies from the Adiabatic-Connection Fluctuation-Dissipation Theorem". Four systems are studied, each of which are detailed in the main paper. The code used to generate all the data is contained in the head directory

Data supporting "Insights from exact exchange-correlation kernels"

This is data associated with the publication "Insights from exact exchange-correlation kernels". Three systems are studied. The plots and plotting scripts for each system are contained within the relevant directories. The code and scripts used to generate the data are included within the "code" directory