Since the great discovery made by Laue, x-ray diffraction has become the most im portant method for the investigation of atomic structure in condensed matter. Cer tain investigations, however, are difficult or totally impossible to conduct using x-rays, for example, the localization of atomic nuclei or atoms having only a few core electrons, and the observation of magnetic moments. The investigation of these important areas is made possible by neutron diffraction. Thus this method has devel oped into an important supplement to x-ray investigations. An ever-increasing de mand is put on the...