Korringa–Kohn–Rostoker method
Korringa–Kohn–Rostoker method
The Korringa–Kohn–Rostoker method or KKR method is used to calculate the electronic band structure of periodic solids. In the derivation of the method using multiple scattering theory by Jan Korringa[1] and the derivation based on the Kohn variational method,[2] the muffin-tin approximation was used.[3] Later calculations are done with full potentials having no shape restrictions.[4][5]
Introduction
Many band theory methods have been proposed over the years. Some of the most widely used, such as the electronic structure programs VASP and WIEN2k, make use of approximations so that acceptable accuracy can be achieved with a minimum of computer resources. The KKR method is chosen when the primary goal is high accuracy.
The parameters obtained from reliable band-theory calculations are useful in theoretical studies of problems, such as superconductivity, for which the density functional theory does not apply.
Mathematical formulation
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![{\displaystyle {m_{lm,l'm'}}=\left[{\alpha \cot {\delta _{l}}\left(E\right)-i\alpha }\right]{\delta _{l,l'}}{\delta _{m,m'}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/a57cfcb4e977eb6cfbccedcb1e242da2ddedd5d4)
