Structure Factor and Radial Distribution Function for Liquid Argon at 85 °K

The structure factor $S(Q)$ for liquid argon at 85 ^∘{}K has been determined in a neutron scattering experiment to an accuracy of {~}0.01. The problem of obtaining $S(Q)$ from the results of neutron scattering measurements, made as a function of scattering angle using a detector with an energy-dependent efficiency, is considered in detail. Smooth curves for $S(Q)$ and its Fourier transform, the radial distribution function $g(r)$, were obtained from the experimental data by an iterative procedure suggested by Verlet and carried out by Schiff, and are tabulated for convenience. The experimental results are in excellent agreement with the predictions of computer simulations based on either the Lennard-Jones two-body interaction, or on the Barker, Fisher, and Watts potential with corrections for three-body and quantum effects included.