A novel and effective fractional-spin correction against the important issue of static correlation in density functional theory is developed. Combined with the fractional-charge correction from recently developed localized orbital scaling correction (LOSC), a new model of functional, termed fractional-spin corrected LOSC (FSLOSC), is proposed. FSLOSC is of the character of derivative discontinuity and largely restores the flat-plane behavior of electronic energy at fractional charges and fractional spins. It significantly improves on results from conventional functionals for the prediction of ionization potentials, electron affinities, quasiparticle spectra, reaction barrier highs. In particular, FSLOSC can properly describe the dissociation of ionic species, single bonds, multiple bonds without breaking space or spin symmetries, and correct the spurious fractional-charge dissociation of heteroatom molecules of conventional functionals. Thus, FSLOSC shows less delocalization error and better treatment of strongly correlated systems.

Describing discontinuity in exchange-correlation functional and strong correlation with fractional-spin correction

255th National Meeting (2018)

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