  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.
