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

We propose a method to calculate the Hubbard U parameter in GGA+U or the α pa

rameter in the atomic self-interaction correction (ASIC) scheme for transition-metal

d orbitals by mapping the self-interaction correction (SIC) onto GGA+U, which is

suitable for atom-centered basis sets. SIC can oﬀer a substitute for the Hubbard

U parameter in GGA+U, although its usage should be limited considering the dif

ferences between GGA+U and SIC. Approximations to reduce computational cost

for self-interaction (SI) corrected localized orbitals are deduced from the properties

of the unitary transformation in SIC and the atomic likeness of molecular orbitals

dominated by transition-metal d orbitals, and the parameters are obtained from the

approximate forms of the localized orbitals. First-row transition-metal complexes

were tested, and the results are comparable to experimental measurements and pre

vious calculations. Our method does not guarantee better results than those of

the linear response method or hybrid functionals, but mapping from SIC suppresses

overestimation of the U parameter to obtain proper geometries and energies for Fe

porphyrin-imidazole, Fe-porphyrin-CO and FeO2 modeling

Abstract