DFT Estimation of Exchange Coupling Constant of Cr8 Molecular Ring using the Hybrid Functional B3LYP
M. Wojciechowskia, B. Brzostowski a and G. Kamieniarz b
aInstitute of Physics, University of Zielona Góra, Prof. Szafrana 4a, 65-516 Zielona Góra, Poland
bFaculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
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A study of electronic and magnetic properties of an octametallic chromium-based homonuclear molecule Cr8F8(CO2-C(CH3)3)16 is presented, using density functional theory (DFT) approach and linearized augmented plane wave (LAPW) method with Perdew, Burke and Ernzerhof (PBE) and Becke 3-term correlation (B3LYP) functionals. The exchange coupling parameters between transition metals ions are extracted, taking into account two different (ferro- and antiferromagnetic) spin configurations. The value J=3.1 meV found for the hybrid B3LYP functional improves significantly the one obtained for the PBE functional and gives an evidence for the superiority of the former in simulation of molecular nanomgnets. Moreover, the hybrid functional yields excellent spin density localisation, an enhancement of the HOMO-LUMO gaps and the value 2.81 μB of magnetic moment at the chromium centre in good agreement with experiment.

DOI: 10.12693/APhysPolA.127.407
PACS numbers: 75.50.Xx, 71.15.Mb, 73.22.-f, 75.30.Et, 31.15.E-, 71.10.-w