Enantiomorphism and multiple-beam X-ray diffraction

It is shown that multiple-beam X-ray diffraction does not provide a means of distinguishing between the two enantiomorphic forms of the same crystal. A detailed proof is presented for the case of benzil. It is also shown that, without anomalous dispersion, multiple-beam diffraction is equally incapable of determining the polarity of acentric crystals. Applications are presented to results published in recent literature. (orig.)