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

  • Dades identificatives

    Identificador: PC:1173
    Autors:
    Josep M. PobletCoen de GraafNuno A. G. BandeiraNadia Ben AmorNicolas SuaudXavier López
    Resum:
    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.
  • Altres:

    Autor segons l'article: Josep M. Poblet Coen de Graaf Nuno A. G. Bandeira Nadia Ben Amor Nicolas Suaud Xavier López
    Departament: Química Física i Inorgànica
    Autor/s de la URV: LÓPEZ FERNÁNDEZ, JAVIER Nicolas Suaud Nadia Ben Amor Nuno A. G. Bandeira DE GRAAF, CORNELIS POBLET RIUS, JOSEP MARIA
    Paraules clau: embedded cluster DDCI polyoxometalates
    Resum: 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.
    Grup de recerca: Química Quàntica
    Àrees temàtiques: Chemistry Química Química
    Accès a la llicència d'ús: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 1549-9618
    Identificador de l'autor: 0000-0002-4533-0623 0000-0001-8114-6658 0000-0002-5754-7328 n/a 0000-0001-9744-7375 0000-0003-0322-6796
    Data d'alta del registre: 2015-05-07
    Pàgina final: 559
    Volum de revista: 11
    Versió de l'article dipositat: info:eu-repo/semantics/acceptedVersion
    Enllaç font original: http://pubs.acs.org/doi/abs/10.1021/ct5010005
    URL Document de llicència: https://repositori.urv.cat/ca/proteccio-de-dades/
    DOI de l'article: 10.1021/ct5010005
    Entitat: Universitat Rovira i Virgili
    Any de publicació de la revista: 2015
    Pàgina inicial: 550
    Tipus de publicació: Article Artículo Article
  • Paraules clau:

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