Articles producció científica> Química Física i Inorgànica

Accuracy of Embedded Fragment Calculation for Evaluating Electron Interactions in Mixed Valence Magnetic Systems: Study of 2e- Reduced Lindqvist Polyoxometalates

  • Identification data

    Identifier: PC:1173
    Authors:
    Josep M. PobletCoen de GraafNuno A. G. BandeiraNadia Ben AmorNicolas SuaudXavier López
    Abstract:
    Accurate quantum chemical calculations on real-world magnetic systems are challenging, the inclusion of electron correlation being the bottleneck of such task. One method proposed to overcome this difficulty is the embedded fragment approach. It tackles a chemical problem by dividing it into small fragments, which are treated in a highly accurate way, surrounded by an embedding included at an approximate level. For the vast family of medium-to-large sized polyoxometalates, two-electron-reduced systems are habitual and their magnetic properties are interesting. In this paper, we aim at assessing the quality of embedded fragment calculations by checking their ability to reproduce the electronic spectra of a complete system, here the mixed-metal series [MoxW6−xO19]4− (x = 0−6). The microscopic parameters extracted from fragment calculations (electron hopping, intersite electrostatic repulsion, local orbital energy, etc.) have been used to reproduce the spectra through model Hamiltonian calculations. These energies are compared to the results of the highly accurate ab initio difference dedicated configuration interaction (DDCI) method on the complete system. In general, the model Hamiltonian calculations using parameters extracted from embedded fragments nearly exactly reproduce the DDCI spectra. This is quite an important result since it can be generalized to any inorganic magnetic system. Finally, the occurrence of singlet or triplet ground states in the series of molecules studied is rationalized upon the interplay of the parameters extracted.
  • Others:

    Author, as appears in the article.: Josep M. Poblet Coen de Graaf Nuno A. G. Bandeira Nadia Ben Amor Nicolas Suaud Xavier López
    Department: Química Física i Inorgànica
    URV's Author/s: LÓPEZ FERNÁNDEZ, JAVIER Nicolas Suaud Nadia Ben Amor Nuno A. G. Bandeira DE GRAAF, CORNELIS POBLET RIUS, JOSEP MARIA
    Keywords: embedded cluster DDCI polyoxometalates
    Abstract: Accurate quantum chemical calculations on real-world magnetic systems are challenging, the inclusion of electron correlation being the bottleneck of such task. One method proposed to overcome this difficulty is the embedded fragment approach. It tackles a chemical problem by dividing it into small fragments, which are treated in a highly accurate way, surrounded by an embedding included at an approximate level. For the vast family of medium-to-large sized polyoxometalates, two-electron-reduced systems are habitual and their magnetic properties are interesting. In this paper, we aim at assessing the quality of embedded fragment calculations by checking their ability to reproduce the electronic spectra of a complete system, here the mixed-metal series [MoxW6−xO19]4− (x = 0−6). The microscopic parameters extracted from fragment calculations (electron hopping, intersite electrostatic repulsion, local orbital energy, etc.) have been used to reproduce the spectra through model Hamiltonian calculations. These energies are compared to the results of the highly accurate ab initio difference dedicated configuration interaction (DDCI) method on the complete system. In general, the model Hamiltonian calculations using parameters extracted from embedded fragments nearly exactly reproduce the DDCI spectra. This is quite an important result since it can be generalized to any inorganic magnetic system. Finally, the occurrence of singlet or triplet ground states in the series of molecules studied is rationalized upon the interplay of the parameters extracted.
    Research group: Química Quàntica
    Thematic Areas: Chemistry Química Química
    licence for use: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 1549-9618
    Author identifier: 0000-0002-4533-0623 0000-0001-8114-6658 0000-0002-5754-7328 n/a 0000-0001-9744-7375 0000-0003-0322-6796
    Record's date: 2015-05-07
    Last page: 559
    Journal volume: 11
    Papper version: info:eu-repo/semantics/acceptedVersion
    Link to the original source: http://pubs.acs.org/doi/abs/10.1021/ct5010005
    Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
    Article's DOI: 10.1021/ct5010005
    Entity: Universitat Rovira i Virgili
    Journal publication year: 2015
    First page: 550
    Publication Type: Article Artículo Article
  • Keywords:

    Fisicoquímica
    Energia -- Càlcul
    Polioxometal·lats
    embedded cluster
    DDCI
    polyoxometalates
    Chemistry
    Química
    Química
    1549-9618
  • Documents:

  • Cerca a google

    Search to google scholar