  Modeling nuclear quantum effects is required for accurate molecular dynamics
(MD) simulations of molecules. The community has paid special attention to
water and other biomolecules that show hydrogen bonding. Standard methods of
modeling nuclear quantum effects like Ring Polymer Molecular Dynamics (RPMD)
are computationally costlier than running classical trajectories. A force-field
functor (FFF) is an alternative method that computes an effective force field
which replicates quantum properties of the original force field. In this work,
we propose an efficient method of computing FFF using the Wigner-Kirkwood
expansion. As a test case, we calculate a range of thermodynamic properties of
Neon, obtaining the same level of accuracy as RPMD, but with the shorter
runtime of classical simulations. By modifying existing MD programs, the
proposed method could be used in the future to increase the efficiency and
accuracy of MD simulations involving water and proteins.
