Articles producció científica> Química Física i Inorgànica

Reduced Common Molecular Orbital Basis for Nonorthogonal Configuration Interaction

  • Identification data

    Identifier: imarina:6389888
    Authors:
    Kathir RKDe Graaf CBroer RHavenith RWA
    Abstract:
    © 2020 American Chemical Society. Electron and charge transfers are part of many vital processes in nature and technology. Ab initio descriptions of these processes provide useful insights that can be utilized for applications. A combination of the embedded cluster material model and nonorthogonal configuration interaction (NOCI), in which the cluster wave functions are expanded in many-electron basis functions (MEBFs) consisting of spin-adapted, antisymmetrized products of multiconfigurational wave functions of fragments (which are usually molecules) in the cluster, appears to provide a compromise between accuracy and calculation time. Additional advantages of this NOCI-Fragments approach are the chemically convenient interpretation of the wave function in terms of molecular states, and the direct accessibility of electronic coupling between diabatic states to describe energy and electron transfer processes. Bottlenecks in this method are the large number of two-electron integrals that have to be handled for the calculation of an electronic coupling matrix element and the enormous number of matrix elements over determinant pairs that have to be evaluated for the calculation of one matrix element between the MEBFs. We show here how we created a reduced common molecular orbital basis that is utilized to significantly reduce the number of two-electron integrals that need to be handled. The results obtained with this basis do not show any loss of accuracy in relevant quantities like electronic couplings and vertical excitation energies. We also show a significant reduction in computation time without loss in accuracy when matrix elements over determinant pairs with small weights are neglected in the NOCI. These improvements in the methodology render NOCI-Fragments to be al
  • Others:

    Author, as appears in the article.: Kathir RK; De Graaf C; Broer R; Havenith RWA
    Department: Química Física i Inorgànica
    URV's Author/s: De Graaf, Cornelis
    Keywords: Valence-bond theory Transport Singlet fission Pentacene Matrix-elements Hole states Hartree-fock theory Exciton Electronic-structure Charge-transfer
    Abstract: © 2020 American Chemical Society. Electron and charge transfers are part of many vital processes in nature and technology. Ab initio descriptions of these processes provide useful insights that can be utilized for applications. A combination of the embedded cluster material model and nonorthogonal configuration interaction (NOCI), in which the cluster wave functions are expanded in many-electron basis functions (MEBFs) consisting of spin-adapted, antisymmetrized products of multiconfigurational wave functions of fragments (which are usually molecules) in the cluster, appears to provide a compromise between accuracy and calculation time. Additional advantages of this NOCI-Fragments approach are the chemically convenient interpretation of the wave function in terms of molecular states, and the direct accessibility of electronic coupling between diabatic states to describe energy and electron transfer processes. Bottlenecks in this method are the large number of two-electron integrals that have to be handled for the calculation of an electronic coupling matrix element and the enormous number of matrix elements over determinant pairs that have to be evaluated for the calculation of one matrix element between the MEBFs. We show here how we created a reduced common molecular orbital basis that is utilized to significantly reduce the number of two-electron integrals that need to be handled. The results obtained with this basis do not show any loss of accuracy in relevant quantities like electronic couplings and vertical excitation energies. We also show a significant reduction in computation time without loss in accuracy when matrix elements over determinant pairs with small weights are neglected in the NOCI. These improvements in the methodology render NOCI-Fragments to be also applicable to treat clusters of larger molecular systems with larger atomic basis sets and larger active spaces, as the computation time becomes dependent on the number of occupied orbitals and less dependent on the size of the active space.
    Thematic Areas: Química Physics, atomic, molecular & chemical Physical and theoretical chemistry Medicina i Materiais Matemática / probabilidade e estatística Interdisciplinar Farmacia Engenharias iii Computer science applications Ciências biológicas ii Ciências biológicas i Ciência da computação Chemistry, physical Chemistry, multidisciplinary Biotecnología Astronomia / física
    licence for use: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 15499618
    Author's mail: coen.degraaf@urv.cat
    Author identifier: 0000-0001-8114-6658
    Record's date: 2023-02-26
    Papper version: info:eu-repo/semantics/publishedVersion
    Link to the original source: https://pubs.acs.org/doi/10.1021/acs.jctc.9b01144
    Papper original source: Journal Of Chemical Theory And Computation. 16 (5): 2941-2951
    APA: Kathir RK; De Graaf C; Broer R; Havenith RWA (2020). Reduced Common Molecular Orbital Basis for Nonorthogonal Configuration Interaction. Journal Of Chemical Theory And Computation, 16(5), 2941-2951. DOI: 10.1021/acs.jctc.9b01144
    Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
    Article's DOI: 10.1021/acs.jctc.9b01144
    Entity: Universitat Rovira i Virgili
    Journal publication year: 2020
    Publication Type: Journal Publications
  • Keywords:

    Chemistry, Multidisciplinary,Chemistry, Physical,Computer Science Applications,Physical and Theoretical Chemistry,Physics, Atomic, Molecular & Chemical
    Valence-bond theory
    Transport
    Singlet fission
    Pentacene
    Matrix-elements
    Hole states
    Hartree-fock theory
    Exciton
    Electronic-structure
    Charge-transfer
    Química
    Physics, atomic, molecular & chemical
    Physical and theoretical chemistry
    Medicina i
    Materiais
    Matemática / probabilidade e estatística
    Interdisciplinar
    Farmacia
    Engenharias iii
    Computer science applications
    Ciências biológicas ii
    Ciências biológicas i
    Ciência da computação
    Chemistry, physical
    Chemistry, multidisciplinary
    Biotecnología
    Astronomia / física
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