Application of the exact muffin-tin orbitals theory: the spherical cell approximation

We present a self-consistent electronic structure calculation method based on the exact muffin-tin orbitals (EMTO) theory developed by O.K. Andersen, O. Jepsen and G. Krier [in: V. Kumar, O.K. Andersen, A. Mookerjee (Eds.), Lectures on Methods of Electronic Structure Calculations, Word Scientific, Singapore, 1994, pp. 63–124] and O.K. Andersen, C. Arcangeli, R.W. Tank, T. Saha-Dasgupta, G. Krier, O. Jepsen and I. Dasgupta [Mater. Res. Soc. Symp. Proc. 491 (1998) 3–34]. The EMTO theory can be considered as an improved screened KKR (Korringa–Kohn–Rostoker) method which is able to treat large overlapping potential spheres. Within the present implementation of the EMTO theory the one-electron equations are solved exactly using Greenʹs function formalism, and Poissonʹs equation is solved within the spherical cell approximation (SCA). To demonstrate the accuracy of the SCA–EMTO method, test calculations have been carried out.