Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide We expand on a recently introduced alternate framework for GW simulation of charged excitations [ Scott, C. J. C. J. Chem. Phys. 2023, 158, 124102 ], based around the conservation of directly computed spectral moments of the GW self-energy. Featuring a number of desirable formal properties over other implementations, we also detail efficiency improvements and a parallelism strategy, resulting in an implementation with a demonstrably similar scaling to an established Hartree–Fock code, with only an order of magnitude increase in cost. We also detail the applicability of a range of self-consistent GW variants within this framework, including a scheme for full self-consistency of all dynamical variables, while avoiding the Matsubara axis or analytic continuation, allowing formal convergence at zero temperature. By investigating a range of self-consistency protocols over the GW 100 molecular test set, we find a little-explored self-consistent variant based around a simpler coupled chemical potential and Fock matrix optimization to be the most accurate self-consistent GW approach. Additionally, we validate recently observed evidence that Tamm–Dancoff-based screening approximations within GW lead to higher accuracy than traditional random phase approximation screening over these molecular test cases. Finally, we consider the Chlorophyll A molecule, finding agreement with experiment within the experimental uncertainty, and a description of the full-frequency spectrum of charged excitations.
Authors: Oliver J. Backhouse, Marcus K. Allen, Charles J. C. Scott, George H. Booth
Institution: King's College London
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4413845580