A series of nine samples of sigma-Fe_{100-x}Mo_x with 44<x<57 were synthesized by a sintering method. The samples were investigated experimentally and theoretically. Using X-ray diffraction techniques structural parameters such as lattice constants,
atomic positions within the unit cell and populations of atoms over five different sublattices were determined. An information on charge-densities and electric field gradients at particular lattice sites was obtained by application of the Korringa-Kohn-Rostoker (KKR) method for electronic structure calculations. Hyperfine quantities calculated with KKR were successfully applied to analyze Mossbauer spectra measured at room temperature.
