Microscopic structure and intermolecular potential in liquid deuterium

We have measured the intermolecular structure factor and its thermodynamic derivatives in the vicinity of the triple point of liquid deuterium, using two different neutron sources. We have also derived the same quantities by using path integral Monte Carlo computer simulations. For the structure factor, we find good agreement between the experiments and the simulation results, using either the Lennard-Jones or a more realistic phenomenological potential. However, when the comparison is extended to the thermodynamic derivatives, a clear difference is observed between the two different intermolecular potentials.