Počet záznamů: 1
The Effect of Geometry, Spin, and Orbital Optimization in Achieving Accurate, Correlated Results for Iron-Sulfur Cubanes
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SYSNO ASEP 0552754 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název The Effect of Geometry, Spin, and Orbital Optimization in Achieving Accurate, Correlated Results for Iron-Sulfur Cubanes Tvůrce(i) Mejuto-Zaera, C. (US)
Tzeli, D. (GR)
Williams-Young, D. B. (US)
Tubman, N. (US)
Matoušek, Mikuláš (UFCH-W)
Brabec, Jiří (UFCH-W) RID, ORCID
Veis, Libor (UFCH-W) RID, ORCID
Xantheas, S. (US)
de Jong, W. A. (US)Zdroj.dok. Journal of Chemical Theory and Computation . - : American Chemical Society - ISSN 1549-9618
Roč. 18, č. 2 (2022), s. 687-702Poč.str. 16 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova matrix renormalization-group ; density-functional theory ; electronic-structure ; quantum-theory ; ab-initio ; photoelectron-spectroscopy ; configuration-interaction ; cluster biosynthesis ; angstrom resolution ; synthetic analogs Vědní obor RIV CF - Fyzikální chemie a teoretická chemie Obor OECD Physical chemistry CEP GJ18-18940Y GA ČR - Grantová agentura ČR Výzkumná infrastruktura IT4Innovations - 90070 - Vysoká škola báňská - Technická univerzita Ostrava Způsob publikování Omezený přístup Institucionální podpora UFCH-W - RVO:61388955 UT WOS 000744521500001 EID SCOPUS 85121952867 DOI 10.1021/acs.jctc.1c00830 Anotace Iron-sulfur clusters comprise an important functional motif in the catalytic centers of biological systems, capable of enabling important chemical transformations at ambient conditions. This remarkable capability derives from a notoriously complex electronic structure that is characterized by a high density of states that is sensitive to geometric changes. The spectral sensitivity to subtle geometric changes has received little attention from correlated, large active space calculations, owing partly to the exceptional computational complexity for treating these large and correlated systems accurately. To provide insight into this aspect, we report the first Complete Active Space Self Consistent Field (CASSCF) calculations for different geometries of the [Fe(II/III)(4)S-4(SMe)(4)](-2) clusters using two complementary, correlated solvers: spin-pure Adaptive Sampling Configuration Interaction (ASCI) and Density Matrix Renormalization Group (DMRG). We find that the previously established picture of a double-exchange driven magnetic structure, with minute energy gaps (<1 mHa) between consecutive spin states, has a weak dependence on the underlying geometry. However, the spin gap between the singlet and the spin state 2S + 1 = 19, corresponding to a maximal number of Fe-d electrons being unpaired and of parallel spin, is strongly geometry dependent, changing by a factor of 3 upon slight deformations that are still within biologically relevant parameters. The CASSCF orbital optimization procedure, using active spaces as large as 86 electrons in 52 orbitals, was found to reduce this gap compared to typical mean-field orbital approaches. Our results show the need for performing large active space calculations to unveil the challenging electronic structure of these complex catalytic centers and should serve as accurate starting points for fully correlated treatments upon inclusion of dynamical correlation outside the active space. Pracoviště Ústav fyzikální chemie J.Heyrovského Kontakt Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Rok sběru 2023 Elektronická adresa http://hdl.handle.net/11104/0327863
Počet záznamů: 1