Abstract
The structure factors of the molten elements Si and Ge were determined by means of neutron diffraction. Together with the structure factors of molten Sn and Pb, taken from literature, specific variations in the run of the curves can be detected. Especially, a shoulder on the larger g-side of the main maximum becomes larger going from Pb to Si. A model is given which describes these melts as being composed of hard spheres and tetrahedra. The concentration of tetrahedra is evaluated