Downfolding from ab initio to interacting model Hamiltonians : comprehensive analysis and benchmarking of the DFT+cRPA approach
(2024) In npj Computational Materials 10(1).- Abstract
Model Hamiltonians are regularly derived from first principles to describe correlated matter. However, the standard methods for this contain a number of largely unexplored approximations. For a strongly correlated impurity model system, here we carefully compare a standard downfolding technique with the best possible ground-truth estimates for charge-neutral excited-state energies and wave functions using state-of-the-art first-principles many-body wave function approaches. To this end, we use the vanadocene molecule and analyze all downfolding aspects, including the Hamiltonian form, target basis, double-counting correction, and Coulomb interaction screening models. We find that the choice of target-space basis functions emerges as a... (More)
Model Hamiltonians are regularly derived from first principles to describe correlated matter. However, the standard methods for this contain a number of largely unexplored approximations. For a strongly correlated impurity model system, here we carefully compare a standard downfolding technique with the best possible ground-truth estimates for charge-neutral excited-state energies and wave functions using state-of-the-art first-principles many-body wave function approaches. To this end, we use the vanadocene molecule and analyze all downfolding aspects, including the Hamiltonian form, target basis, double-counting correction, and Coulomb interaction screening models. We find that the choice of target-space basis functions emerges as a key factor for the quality of the downfolded results, while orbital-dependent double-counting corrections diminish the quality. Background screening of the Coulomb interaction matrix elements primarily affects crystal-field excitations. Our benchmark uncovers the relative importance of each downfolding step and offers insights into the potential accuracy of minimal downfolded model Hamiltonians.
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- author
- organization
- publishing date
- 2024-12
- type
- Contribution to journal
- publication status
- published
- subject
- in
- npj Computational Materials
- volume
- 10
- issue
- 1
- article number
- 129
- publisher
- Nature Publishing Group
- external identifiers
-
- scopus:85196553948
- ISSN
- 2057-3960
- DOI
- 10.1038/s41524-024-01314-6
- language
- English
- LU publication?
- yes
- id
- 37a0af99-096b-40bf-94c5-f4dae336d530
- date added to LUP
- 2024-07-01 14:27:24
- date last changed
- 2024-07-01 14:27:47
@article{37a0af99-096b-40bf-94c5-f4dae336d530,
abstract = {{<p>Model Hamiltonians are regularly derived from first principles to describe correlated matter. However, the standard methods for this contain a number of largely unexplored approximations. For a strongly correlated impurity model system, here we carefully compare a standard downfolding technique with the best possible ground-truth estimates for charge-neutral excited-state energies and wave functions using state-of-the-art first-principles many-body wave function approaches. To this end, we use the vanadocene molecule and analyze all downfolding aspects, including the Hamiltonian form, target basis, double-counting correction, and Coulomb interaction screening models. We find that the choice of target-space basis functions emerges as a key factor for the quality of the downfolded results, while orbital-dependent double-counting corrections diminish the quality. Background screening of the Coulomb interaction matrix elements primarily affects crystal-field excitations. Our benchmark uncovers the relative importance of each downfolding step and offers insights into the potential accuracy of minimal downfolded model Hamiltonians.</p>}},
author = {{Chang, Yueqing and van Loon, Erik G.C.P. and Eskridge, Brandon and Busemeyer, Brian and Morales, Miguel A. and Dreyer, Cyrus E. and Millis, Andrew J. and Zhang, Shiwei and Wehling, Tim O. and Wagner, Lucas K. and Rösner, Malte}},
issn = {{2057-3960}},
language = {{eng}},
number = {{1}},
publisher = {{Nature Publishing Group}},
series = {{npj Computational Materials}},
title = {{Downfolding from ab initio to interacting model Hamiltonians : comprehensive analysis and benchmarking of the DFT+cRPA approach}},
url = {{http://dx.doi.org/10.1038/s41524-024-01314-6}},
doi = {{10.1038/s41524-024-01314-6}},
volume = {{10}},
year = {{2024}},
}