The Microscopic Structure of the Hydrogen Liquids

We have measured the microscopic structure of liquid para-hydrogen using a neutron diffraction experiment on the D4C liquids diffractometer at Institute Laue Langevin (Grenoble, France). This is the first direct neutron diffraction measurement of the static structure factor of hydrogen. The present determination of the microscopic structure of hydrogen is consistent with previous experimental determinations carried out on liquid deuterium and with Path Integral Monte Carlo simulations. The comparison with recent X-ray determinations is also satisfactory.