Self-interaction correction in multiple scattering theory

Abstract

We propose a simplified version of self-interaction corrected local spin-density (SIC-LSD) approximation, based on multiple scattering theory, which implements self-interaction correction locally, within the KKR method. The multiple scattering aspect of this new SIC-LSD method allows for the description of crystal potentials which vary from site to site in a random fashion and the calculation of physical quantities averaged over ensembles of such potentials using the coherent potential approximation (CPA). This facilitates applications of the SIC to alloys and pseudoalloys which could describe disordered local moment systems, as well as intermediate valences. As a demonstration of the method, we study the well-known α-γ phase transition in Ce, where we also explain how SIC operates in terms of multiple scattering theory.

Structural phase transitions and fundamental band gaps ofMgxZn1−xOalloys from first principles

“…It is further shown how the hybridization between Zn-3d and O-2p states affects the width of the band gap, by comparing results obtained within the LSDA with those obtained by applying the self-interaction correction. 46,47 The validity of the present approach, especially the use of the CPA, is discussed by comparing our results with those of previous studies. 37,40,41 In summary, our study addresses important issues in Mg x Zn 1−x O alloys which, with respect to magnetic tunnel junctions, might also be relevant for magnetoelectronics.…”

“…An improved description of localized electrons is achieved by the self-interaction correction 46,47 in which the unphysical self-interaction is removed from the LSDA exchange-correlation functional. In this approach, SIC is applied to various configurations of localized electron states, and the configuration with the lowest total energy defines the ground state energy and configuration.…”

Theory of electronic transport in random alloys with short-range order: Korringa-Kohn-Rostoker nonlocal coherent potential approximation

“…In particular, in combination with density functional theory [2][3][4][5] ͑DFT͒ and the Korringa-Kohn-Rostoker method of band theory, [6][7][8] it provides a fully first-principles description of such systems. A long history of successful applications [9][10][11][12][13][14] attests to the utility and accuracy to which the method is capable.…”

Verification of Anderson Superexchange in MnO via Magnetic Pair Distribution Function Analysis andab initioTheory

“…In this Letter, we utilize magnetic pair distribution function (mPDF) analysis [13], a recently developed method for investigating local magnetic structure, to measure directly the short-range magnetic correlations in the paramagnetic state of MnO from temperature-dependent neutron total scattering experiments. We use these results to evaluate competing theories of magnetic exchange in MnO, finding that the Anderson superexchange [1] obtained from recent DFT calculations with the self-interaction-corrected (SIC) local spin density approximation [14,15] in the "disordered local moment" (DLM) approach [16,17] describes the data exceptionally well with no need for an additional direct exchange contribution present in other models. In addition to resolving this longstanding question about MnO, this work highlights the mPDF technique and the DLM-DFT(+SIC) scheme as valuable tools for studying the magnetic properties of strongly correlated electron systems.…”