# Ab-initio theory for disordered systems with SRO

The field of `first-principles' electronic structure calculations is developing rapidly in line with the growth of powerful computing resources. It is now possible to tackle problems which are not only of fundamental interest but also have real technological relevance. Since all real materials are disordered the ab-initio modelling must include the influence this disorder has on electronic motion. Typically however there is order over small length scales, namely Short Range Order (SRO) which can vary dramatically. Until recently its effects on the electronic structure had been neglected. A method for modelling disordered materials (the KKR-NLCPA) has recently been developed which can address this shortcoming. Further information on this approach is available from the publications listed below.

**Introduction of the KKR-NLCPA, theoretical formalism, implementation schemes and demonstration for a 1d model:**

*Korringa-Kohn-Rostoker nonlocal coherent-potential approximation* by D. A. Rowlands, J. B. Staunton and B. L. Gyorffy, Phys.Rev.B **67,** 115109, (2003).

**Application to describe short-range order effects on electronic structure of compositionally disordered brass alloys:**

*Effects of short-range order on the electronic structure of disordered metallic systems* by D.A. Rowlands, J.B. Staunton, B.L. Gyorffy, B. Ginatempo and E. Bruno, Phys.Rev.B **72**, 045101, (2005).

**Description of fully ab-initio electronic density functional theory of disordered metallic systems with short-range order:**

* Density functional theory for disordered alloys with short-range order: Systematic inclusion of charge-correlation effects *by D.A. Rowlands, A. Ernst, B.L. Gyorffy and J.B. Staunton, Phys.Rev.B **73**, 165122, (2006).

**The Bloch spectral function A**_{B}(**k,E) coarse-grained over the Brillouin zone and at centres of `tiles' for disordered systems with SRO:**

*Nonsite diagonal properties from the Korringa-Kohn-Rostocker nonlocal coherent-potential approximation* by P.R. Tulip, J.B. Staunton, D.A. Rowlands, B.L. Gyorffy, E. Bruno and B. Ginatempo, Phys.Rev.B **73**, 205109, (2006).

**The Bloch spectral function A**_{B}(**k,E) for any wave-vector:**(see figures below)

*Nonlocal spectral properties of disordered alloys* by G. M. Batt and D. A. Rowlands, J.Phys. Condensed Matter **18**, 11031 (2006).

**Effect of SRO on transport properties in disordered systems:**

*Theory of electronic transport in random alloys with short-range order: Korringa-Kohn-Rostoker non-local coherent potential approximation* by P.R. Tulip, J.B. Staunton, S. Lowitzer, D. Koedderitzsch and H. Ebert, Phys.Rev.B **77**, 165116, (2008). (Editors' suggestion)