U.S. Department of Energy Office of Scientific and Technical Information
Generalized single excitation configuration interaction: an investigation into the impact of the inclusion of non-orthogonality on the calculation of core-excited states
Journal Article·· Physical Chemistry Chemical Physics. PCCP
Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Chemical Sciences Div.
California Institute of Technology (CalTech), Pasadena, CA (United States). Div. of Chemistry and Chemical Engineering
In this paper, we investigate different non-orthogonal generalizations of the configuration interaction with single substitutions (CIS) method for the calculation of core-excited states. Fully non-orthogonal CIS (NOCIS) has been described previously for species with singlet and doublet ground states, and this paper reports the extension to molecules in their triplet ground state. In addition to NOCIS, we present a novel method, one-center NOCIS (1C-NOCIS), for open-shell molecules which is intermediate between NOCIS and the computationally less demanding static exchange approximation (STEX). We explore this hierarchy of spin-pure methods for core excitations of molecules with singlet, doublet, and triplet ground states. We conclude that, while NOCIS provides the best results and preserves the spatial symmetry of the wavefunction, 1C-NOCIS retains much of the accuracy of NOCIS at a dramatically reduced cost. For molecules with closed-shell ground states, STEX and 1C-NOCIS are identical.
Oosterbaan, Katherine J., et al. "Generalized single excitation configuration interaction: an investigation into the impact of the inclusion of non-orthogonality on the calculation of core-excited states." Physical Chemistry Chemical Physics. PCCP, vol. 22, no. 15, Mar. 2020. https://doi.org/10.1039/c9cp06592j
Oosterbaan, Katherine J., White, Alec F., Hait, Diptarka, & Head-Gordon, Martin (2020). Generalized single excitation configuration interaction: an investigation into the impact of the inclusion of non-orthogonality on the calculation of core-excited states. Physical Chemistry Chemical Physics. PCCP, 22(15). https://doi.org/10.1039/c9cp06592j
Oosterbaan, Katherine J., White, Alec F., Hait, Diptarka, et al., "Generalized single excitation configuration interaction: an investigation into the impact of the inclusion of non-orthogonality on the calculation of core-excited states," Physical Chemistry Chemical Physics. PCCP 22, no. 15 (2020), https://doi.org/10.1039/c9cp06592j
@article{osti_1779241,
author = {Oosterbaan, Katherine J. and White, Alec F. and Hait, Diptarka and Head-Gordon, Martin},
title = {Generalized single excitation configuration interaction: an investigation into the impact of the inclusion of non-orthogonality on the calculation of core-excited states},
annote = {In this paper, we investigate different non-orthogonal generalizations of the configuration interaction with single substitutions (CIS) method for the calculation of core-excited states. Fully non-orthogonal CIS (NOCIS) has been described previously for species with singlet and doublet ground states, and this paper reports the extension to molecules in their triplet ground state. In addition to NOCIS, we present a novel method, one-center NOCIS (1C-NOCIS), for open-shell molecules which is intermediate between NOCIS and the computationally less demanding static exchange approximation (STEX). We explore this hierarchy of spin-pure methods for core excitations of molecules with singlet, doublet, and triplet ground states. We conclude that, while NOCIS provides the best results and preserves the spatial symmetry of the wavefunction, 1C-NOCIS retains much of the accuracy of NOCIS at a dramatically reduced cost. For molecules with closed-shell ground states, STEX and 1C-NOCIS are identical.},
doi = {10.1039/c9cp06592j},
url = {https://www.osti.gov/biblio/1779241},
journal = {Physical Chemistry Chemical Physics. PCCP},
issn = {ISSN 1463-9076},
number = {15},
volume = {22},
place = {United States},
publisher = {Royal Society of Chemistry},
year = {2020},
month = {03}}