Screened Exchange Corrections to the Random Phase Approximation from Many-Body Perturbation Theory

Author(s)
Felix Hummel, Andreas Grüneis, Georg Kresse, Paul Ziesche
Abstract

The random phase approximation (RPA) systematically overestimates the magnitude of the correlation energy and generally underestimates cohesive energies. This originates in part from the complete lack of exchange terms that would otherwise cancel Pauli exclusion principle violating (EPV) contributions. The uncanceled EPV contributions also manifest themselves in form of an unphysical negative pair density of spin parallel electrons close to electron-electron coalescence. We follow considerations of many-body perturbation theory to propose an exchange correction that corrects the largest set of EPV contributions, while having the lowest possible computational complexity. The proposed method exchanges adjacent particle/hole pairs in the RPA diagrams, considerably improving the pair density of spin-parallel electrons close to coalescence in the uniform electron gas (UEG). The accuracy of the correlation energy is comparable to other variants of second-order screened exchange (SOSEX) corrections although it is slightly more accurate for the spin-polarized UEG. Its computational complexity scales as O(N-5) or O(N-4) in orbital space or real space, respectively. Its memory requirement scales as O(N-2).

Organisation(s)
Computational Materials Physics
External organisation(s)
Technische Universität Wien, Max-Planck-Institut für Physik komplexer Systeme
Journal
Journal of Chemical Theory and Computation
Volume
15
Pages
3223-3236
No. of pages
14
ISSN
1549-9618
DOI
https://doi.org/10.1021/acs.jctc.8b01247
Publication date
05-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/screened-exchange-corrections-to-the-random-phase-approximation-from-manybody-perturbation-theory(089ca251-7bb2-492d-ad17-fe3295702fad).html