Real space full potential multiple scattering theory

We show how to implement a Full Potential Multiple Scattering (fpms) code based on a real-space FPMS theory valid for both continuum and bound states, under conditions for space partitioning that are less restrictive than those applied so far. This theory is free from the need to expand cell shape functions in spherical harmonics or to use rectangular matrices. Tests of the program show that it is able to reproduce with very good accuracy known solutions of the Schrödinger equation. Applications to the spectroscopy of low dimensional systems, such as one-dimensional (1D) chain like systems, 2D layered systems and 3D diamond structure systems, where the Muffin-Tin approximation is known to give very poor results, show a remarkable improvement toward the agreement with experiments. The default mode of the code uses superimposed atomic charge densities, which works satisfactorily in most of the applications, but with help of the es2ms interface, incorporated in the program, one can also use self-consistent charge densities derived from the vasp program. The program is also incorporated in the photoelectron diffraction code msspec and parallelized for energy point.