The FPMS program is the generalization of the multiple scattering theory to overcome the muffin-tin approximation for the shape of the potential, which is widely used due to the strong simplification brought about in the numrical solution of the three-dimensional Schrodinger equation. This new approch is based on a alternative derivation of the full potential multuple scattering equations that allows us to work with square matrices for the phase function and for the cell matrix with only one truncation parameter, overcoming strong traditional difficulties in the literature in the implementation of this method.
Now our new program for X-ray absorption spectroscopies, which so called a Full Potential Multiple Scattering (FPMS) code, were developed. This method generalized multiple scattering program. This problem had been investigated in the past 30years by several groups of solid states physicists and quantum molecular chemists. However there was no clear solutions and in these earlier formulations od the theory the simplicity and the easy of application of the muffin-tin approximation was lost. In our formulation we recuperated such nice features, due to a new, very efficient to solve locally the Schrodinger equation.
We calculated the absorption spectra in molecules and solids where it was known that the muffin-tin approximation badly failed (e.g. the K-edge of Si crystal, the L$_2,3$-edge of SiO$_2$, diatomic molecules in general). We got the quietly good results. We are very confident that we will obtain many good results on by our new scheme for any kind of materials.