Strong Electron Correlation in Nitrogenase Cofactor, FeMoco

dc.contributor.authorMontgomery, Jason M.
dc.contributor.authorMazziotti, David A.
dc.date.accessioned2022-10-19T00:52:37Z
dc.date.available2022-10-19T00:52:37Z
dc.date.issued2018
dc.description.abstractFeMoco, MoFe$_7$S$_9$C, has been shown to be the active catalytic site for the reduction of nitrogen to ammonia in the nitrogenase protein. An understanding of its electronic structure including strong electron correlation is key to designing mimic catalysts capable of ambient nitrogen fixation. Active spaces ranging from [54, 54] to [65, 57] have been predicted for a quantitative description of FeMoco's electronic structure. However, a wavefunction approach for a singlet state using a [54,54] active space would require 10$^{29}$ variables. In this work, we systematically explore the active-space size necessary to qualitatively capture strong correlation in FeMoco and two related moieties, MoFe$_3$S$_7$ and Fe$_4$S$_7$. Using CASSCF and 2-RDM methods, we consider active-space sizes up to [14,14] and [30,30], respectively, with STO-3G, 3-21G, and DZP basis sets and use fractional natural-orbital occupation numbers to assess the level of multireference electron correlation, an examination of which reveals a competition between single-reference and multi-reference solutions to the electronic Schr\"{o}dinger equation for smaller active spaces and a consistent multi-reference solution for larger active spaces.en_US
dc.identifier.citationMontgomery, J. M., & Mazziotti, D. A. (2018). Strong Electron Correlation in Nitrogenase Cofactor, FeMoco. https://doi.org/10.1021/acs.jpca.8b00941en_US
dc.identifier.issn10895639
dc.identifier.uriDOI: 10.1021/acs.jpca.8b00941
dc.identifier.urihttps://search.ebscohost.com/login.aspx?direct=true&AuthType=shib&db=edsarx&AN=edsarx.1805.08746&site=eds-live&scope=site&custid=s5615486
dc.identifier.urihttp://hdl.handle.net/11416/860
dc.language.isoen_USen_US
dc.publisherACS Publicationsen_US
dc.subjectPhysics - Chemical Physicsen_US
dc.titleStrong Electron Correlation in Nitrogenase Cofactor, FeMocoen_US
dc.typeWorking Paperen_US

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