#
APS March Meeting 2016

## Volume 61, Number 2

##
Monday–Friday, March 14–18, 2016;
Baltimore, Maryland

### Session B31: Advances in Density Functional Theory II

11:15 AM–2:15 PM,
Monday, March 14, 2016

Room: 331

Sponsoring
Unit:
DCP

Chair: John Perdew, Temple University

Abstract ID: BAPS.2016.MAR.B31.1

### Abstract: B31.00001 : Self-Interaction Corrected Density Functional Approximations with Unitary Invariance: Applications to Molecules

11:15 AM–11:51 AM

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Abstract

####
Author:

Mark Pederson

(Department of Chemistry, Johns Hopkins University)

For a system of 2N electrons, the Fermi-hole may be interpreted as the square of a normalized "Fermi orbital", $F({\bf a}) \equiv \rho_\sigma({\bf a},{\bf r})/\sqrt{\rho_\sigma({\bf a})}$. This normalized orbital captures all of the spin density at its position of definition, or descriptor, $({\bf a})$. Given a set of N quasi-classical electronic positions $({\bf a_i})$ and a spin density-matrix composed of N Kohn-Sham orbitals, the resulting set of Fermi orbitals may then be used to construct a set of localized Loewdin-orthonormalized orbitals[1]. These orbitals are explicitly a functional of the spin density and are related to the Kohn-Sham orbitals by a unitary transformation that is parametrically dependent on the set quasi-classical electronic descriptors. The construction of such localized orbitals allows for the restoration of unitary invariance into the original Perdew-Zunger self-interaction correction[2,3] and provides a possible simplification compared to the localization-equation based solution of self-interaction corrected functionals[4]. This talk will discuss the construction of this Fermi-orbital-based self-interaction corrected method and the minimization algorithm that relies upon analytical derivatives[3] of the self-interaction energy with respect to the Fermi-orbital descriptors. Recent applications to a large set of molecules including aromatic molecules, molecules with open transition-metal centers, and molecules with frustrated Kekule' structures will be discussed. Initial applications indicate improvements in atomization energies of pi-bonded systems and demonstrate the desired downward shift of orbital energies relative to their Kohn-Sham counterparts.
[1]W.L.Luken and D.N. Beratan, Theo. Chim. Acta {\bf 61}, 265-281 (1982).
[2]M.R. Pederson, A. Ruzsinszky and J. P. Perdew, J. Chem. Phys. ${\bf 140}$, 121103 (2014).
[3]M.R. Pederson and T. Baruah, Advance in Atomic, Molecular and Optical Physics ${\bf 64}$, 153-180 (2015).
[4]M. R. Pederson, R. A. Heaton, and C. C. Lin, J. Chem. Phys. ${\bf 80}$, 1972 (1984).

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2016.MAR.B31.1