Self Interaction Corrected Density Functional Theory
Density functional theory (DFT) is the quantum mechanics approach at the heart of nearly all atomistic modeling in chemistry and materials science today. Computer calculations based on DFT are remarkably successful in describing the properties of molecules, surfaces, and solids when atoms are near their equilibrium positions. Quantities such as bond lengths, bond angles, and vibrational frequencies computed using modern DFT methods agree closely with experimentally-determined values. And because the calculations use only the positions and identities of the atoms as inputs – and not additional parameters that must be tuned in order to achieve accurate results – they have predictive power. Many properties can be reliably predicted even for imagined materials that are yet to be synthesized. This makes DFT calculations a key part of research campaigns to develop new materials for application in technologies like advanced batteries or solar cells.
Despite this success, self-interaction error (SIE) is a flaw that plagues DFT calculations, its effects surfacing most dramatically when electrons are shared over stretched bonds, as in the transition states of chemical reactions, or in many transition metal complexes even near equilibrium geometries. The Fermi-Löwdin orbital self-interaction correction (FLOSIC) method is a promising new approach for removing SIE from DFT calculations. Work in this Center involves further development and implementation of FLOSIC. The research spans a wide range, from basic theory, to software development, to applications.
"...efficient density functional theory calculations without self-interaction ..."