DFT Calculations for Structural, Electronic, and Magnetic Properties of ZnFe₂O₄ Spinel Oxide: The Role of Exchange-Correlation Functional

In this study, quantum-mechanical calculations in the framework of the Density Functional Theory (DFT) were performed to investigate the role of exchange-correlation functional in describing structural, electronic, and magnetic properties of ZnFe₂O₄. Herein B3LYP, PBE0, B1WC, and WC1LYP functionals implemented in the CRYSTAL17 code were considered due to the different amounts of the exact Hartree-Fock exchange fraction. In particular, the role of HF fraction on ZnFe₂O₄ properties was addressed for the first time. Indeed, structural, electronic, and magnetic properties indicate the dependence upon the exchange fraction, where WC1LYP with a 16% exact HF exchange exhibits the best performance compared to the other hybrid functionals. The obtained results reveal an excellent agreement for bandgap, local magnetic moment, long-range magnetic ordering, and unit-cell lattice parameters, overcoming previous theoretical studies based on local/semilocal exchange-correlation treatments. These results confirm the importance of hybrid HF/DFT with controlled HF term contribution to describe the essential features of strongly correlated materials.

Keywords:
ZnFe₂O₄; Antiferromagnetic; DFT; Exchange-correlation functional; WC1LYP