{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T05:22:47Z","timestamp":1788326567398,"version":"build-2803163510"},"reference-count":23,"publisher":"American Chemical Society (ACS)","issue":"10","license":[{"start":{"date-parts":[[2019,9,12]],"date-time":"2019-09-12T00:00:00Z","timestamp":1568246400000},"content-version":"vor","delay-in-days":27,"URL":"https:\/\/pubs.acs.org\/page\/policy\/authorchoice_termsofuse.html"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2019,10,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Quantum chemistry methods that describe excited states on the same footing as the ground state are generally scarce. In previous work, (Gill; et al.J. Phys. Chem. A, 112, 2008, 13164. and later Sundstrom; ; Head-GordonJ. Chem. Phys., 140, 2014, 114103.) considered excited states resulting from a nonorthogonal configuration interaction (NOCI) on stationary solutions of the Hartree\u2013Fock equations. We build upon those contributions and present the state-averaged resonating Hartree\u2013Fock (sa-ResHF) method, which differs from NOCI in that spin-projection and orbital relaxation effects are incorporated from the onset. Our results in a set of small molecules (alanine, formaldehyde, acetaldehyde, acetone, formamide, and ethylene) suggest that sa-ResHF excitation energies are a notable improvement over configuration interaction singles, at a mean-field computational cost. The orbital relaxation in sa-ResHF, carried out in the presence of a spin-projection operator, generally results in excitation energies that are closer to the EOM-CCSD and experimental values than the corresponding NOCI ones.<\/jats:p>","DOI":"10.1021\/acs.jctc.9b00579","type":"journal-article","created":{"date-parts":[[2019,8,16]],"date-time":"2019-08-16T13:13:42Z","timestamp":1565961222000},"page":"5343-5351","source":"Crossref","is-referenced-by-count":14,"title":["Low-Cost Molecular Excited States from a State-Averaged\nResonating Hartree\u2013Fock Approach"],"prefix":"10.1021","volume":"15","author":[{"given":"Jacob","family":"Nite","sequence":"first","affiliation":[{"name":"Wesleyan University , , ,","place":["Middletown, Connecticut, United States, 06459"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1170-1163","authenticated-orcid":true,"given":"Carlos A.","family":"Jime\u0301nez-Hoyos","sequence":"additional","affiliation":[{"name":"Wesleyan University , , ,","place":["Middletown, Connecticut, United States, 06459"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2019,8,16]]},"reference":[{"key":"2026090200540045300_cit1","doi-asserted-by":"publisher","DOI":"10.1063\/1.4809571","article-title":"Communication: An Inexpensive, Variational,\nAlmost Black-Box, Almost Size-Consistent Correction to Configuration\nInteraction Singles for Valence Excited States","volume":"138","author":"Liu","year":"2013","journal-title":"J. Chem. Phys."},{"key":"2026090200540045300_cit2","doi-asserted-by":"publisher","DOI":"10.1063\/1.5045056","article-title":"Communication:\nA Mean Field Platform for Excited State\nQuantum Chemistry","volume":"149","author":"Shea","year":"2018","journal-title":"J. Chem. Phys."},{"key":"2026090200540045300_cit3","doi-asserted-by":"publisher","first-page":"2966","DOI":"10.1021\/acs.jctc.8b01259","article-title":"Non-Orthogonal Configuration Interaction\nwith Single Substitutions for Core-Excited States: An Extension to\nDoublet Radicals","volume":"15","author":"Oosterbaan","year":"2019","journal-title":"J. Chem. Theory Comput."},{"key":"2026090200540045300_cit4","doi-asserted-by":"publisher","DOI":"10.1063\/1.4840097","article-title":"Excited Electronic\nStates from a Variational Approach Based on Symmetry-Projected Hartree\u2013Fock\nConfigurations","volume":"139","author":"Jime\u0301nez-Hoyos","year":"2013","journal-title":"J. Chem. Phys."},{"key":"2026090200540045300_cit5","doi-asserted-by":"publisher","first-page":"13164","DOI":"10.1021\/jp801738f","article-title":"Self-Consistent Field Calculations\nof Excited States Using the Maximum Overlap Method (MOM)","volume":"112","author":"Gilbert","year":"2008","journal-title":"J. Phys. Chem. A"},{"key":"2026090200540045300_cit6","doi-asserted-by":"publisher","first-page":"2908","DOI":"10.1063\/1.432552","article-title":"The Two\nLowest Energy 2A\u2032 States of NO2","volume":"64","author":"Jackels","year":"1976","journal-title":"J. Chem.\nPhys."},{"key":"2026090200540045300_cit7","doi-asserted-by":"publisher","first-page":"253","DOI":"10.1016\/0301-0104(81)80206-6","article-title":"A Method for Describing\nResonance between Generalized\nValence Bond Wavefunctions","volume":"57","author":"Voter","year":"1981","journal-title":"Chem. 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L.; Williams-Young, D.; Ding, F.; Lipparini, F.; Egidi, F.; Goings, J.; Peng, B.; Petrone, A.; Henderson, T.; Ranasinghe, D.; Zakrzewski, V. G.; Gao, J.; Rega, N.; Zheng, G.; Liang, W.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Throssell, K.; Montgomery, J. A., Jr.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Keith, T. A.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A. P.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Millam, J. M.; Klene, M.; Adamo, C.; Cammi, R.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Farkas, O\u0308.; Foresman, J. B.; Fox, D. 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