Neutron diffraction on mercury: density dependence of the static structure factor

We report on a new neutron diffraction determination of the static structure factor of liquid mercury at room temperature. By applying pressure on the sample up to 2 kbar (giving a density change of about 0.8%), it has been possible to measure, for the first time for mercury, the isothermal density derivative of the static structure factor. This quantity, in the case of simple insulating fluids, has already been shown to be more sensitive than the structure factor itself to the details of the interatomic potential.