arrow
Return

Efficient Quasiparticle Determination beyond the Diagonal Approximation via Random Compression

delete2024-01-04
delete3
delete
OA
AI
A
Annabelle Canestraight *
X
Xiaohe Lei
K
Khaled Z. Ibrahim
V
Vojtěch Vlček
DOI:10.1021/acs.jctc.3c01069delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
Calculations of excited states in the Green's function formalism often invokes the diagonal approximation, in which the quasiparticle states are taken from a mean-field calculation. In this paper, we extend the stochastic approaches applied in the many-body perturbation theory and overcome this limitation for large systems in which we are interested in a small subset of states. We separate the problem into a core subspace whose coupling to the remainder of the system environment is stochastically sampled. This method is exemplified on computing hole injection energies into CO2 on an extended gold surface with nearly 3000 electrons. We find that in the extended system the size of the problem can be compressed up to 95% using stochastic sampling. This result provides a way forward for self-consistent stochastic methods and determination of Dyson orbitals in large systems.
Keywords:
ELECTRONIC EXCITATIONS
GREENS-FUNCTION
GW CALCULATIONS

Journal

Journal of Chemical Theory and Computation cover
Journal of Chemical Theory and Computation
IF:
5.5
Papers:
1.1W
Citations:
5.4W

Organization

U
University of California Santa Barbara
Scholars:
1.2W
Papers: 9.6K
Citations: 3.6W
University of California System cover
University of California System
Scholars:
37.5W
Papers: 33.7W
Citations: 6.6K