Estimation of Effective Parameters for the Transition-Metal Complexes by Mapping Self-Interaction Correction onto GGA+U

<div><div>We propose a method to calculate the Hubbard U parameter in GGA+U or the α pa</div><div>rameter in the atomic self-interaction correction (ASIC) scheme for transition-metal</div><div>d orbitals by mapping the self-interaction correction (SIC) onto GGA+U, which is</div><div>suitable for atom-centered basis sets. SIC can offer a substitute for the Hubbard</div><div>U parameter in GGA+U, although its usage should be limited considering the dif</div><div>ferences between GGA+U and SIC. Approximations to reduce computational cost</div><div>for self-interaction (SI) corrected localized orbitals are deduced from the properties</div><div>of the unitary transformation in SIC and the atomic likeness of molecular orbitals</div><div>dominated by transition-metal d orbitals, and the parameters are obtained from the</div><div>approximate forms of the localized orbitals. First-row transition-metal complexes</div><div>were tested, and the results are comparable to experimental measurements and pre</div><div>vious calculations. Our method does not guarantee better results than those of</div><div>the linear response method or hybrid functionals, but mapping from SIC suppresses</div><div>overestimation of the U parameter to obtain proper geometries and energies for Fe</div><div>porphyrin-imidazole, Fe-porphyrin-CO and FeO2 modeling</div></div>