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Challenges for density functional theory in simulating metal-metal singlet bonding: A case study of dimerized VO2.
Zhang, Yubo; Ke, Da; Wu, Junxiong; Zhang, Chutong; Hou, Lin; Lin, Baichen; Chen, Zuhuang; Perdew, John P; Sun, Jianwei.
Afiliación
  • Zhang Y; Minjiang Collaborative Center for Theoretical Physics, College of Physics and Electronic Information Engineering, Minjiang University, Fuzhou, China.
  • Ke D; Minjiang Collaborative Center for Theoretical Physics, College of Physics and Electronic Information Engineering, Minjiang University, Fuzhou, China.
  • Wu J; Minjiang Collaborative Center for Theoretical Physics, College of Physics and Electronic Information Engineering, Minjiang University, Fuzhou, China.
  • Zhang C; Minjiang Collaborative Center for Theoretical Physics, College of Physics and Electronic Information Engineering, Minjiang University, Fuzhou, China.
  • Hou L; Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA.
  • Lin B; School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Republic of Singapore.
  • Chen Z; Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore 138634, Republic of Singapore.
  • Perdew JP; School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China.
  • Sun J; Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China.
J Chem Phys ; 160(13)2024 Apr 07.
Article en En | MEDLINE | ID: mdl-38557836
ABSTRACT
VO2 is renowned for its electric transition from an insulating monoclinic (M1) phase, characterized by V-V dimerized structures, to a metallic rutile (R) phase above 340 K. This transition is accompanied by a magnetic change the M1 phase exhibits a non-magnetic spin-singlet state, while the R phase exhibits a state with local magnetic moments. Simultaneous simulation of the structural, electric, and magnetic properties of this compound is of fundamental importance, but the M1 phase alone has posed a significant challenge to the density functional theory (DFT). In this study, we show none of the commonly used DFT functionals, including those combined with on-site Hubbard U to treat 3d electrons better, can accurately predict the V-V dimer length. The spin-restricted method tends to overestimate the strength of the V-V bonds, resulting in a small V-V bond length. Conversely, the spin-symmetry-breaking method exhibits the opposite trends. Each of these two bond-calculation methods underscores one of the two contentious mechanisms, i.e., Peierls lattice distortion or Mott localization due to electron-electron repulsion, involved in the metal-insulator transition in VO2. To elucidate the challenges encountered in DFT, we also employ an effective Hamiltonian that integrates one-dimensional magnetic sites, thereby revealing the inherent difficulties linked with the DFT computations.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: J Chem Phys Año: 2024 Tipo del documento: Article País de afiliación: China Pais de publicación: Estados Unidos
Texto completo
Añadir a Mi BVS
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XML
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: J Chem Phys Año: 2024 Tipo del documento: Article País de afiliación: China Pais de publicación: Estados Unidos