Microscopic structure factor of liquid parahydrogen: Monte Carlo and molecular dynamics simulations

We present a comparison of results on the microscopic structure of liquid parahydrogen as calculated by path-integral Monte Carlo and path-integral-centroid-molecular-dynamics simulations. The radial distribution functions calculated using both approaches are found to be in good agreement. The disagreement between published estimates for the static structure factor are found to arise from different approximations followed for the Fourier transform of heavily truncated data. A comparison of the structure of the real liquid with that of a classical analog is also made and shows that the latter would freeze at the experimental liquid density. Liquid parahydrogen is therefore stabilized by the action of large quantum effects.