public class VirialHePCKLJS
Computes additive virial coefficients using the pair potential for He of Przybytek et al. (2010) Phys. Rev. Lett. 104, 183003.
Use QFH boolean to change pair potential to the quadratic Feynman-Hibbs potential.
If determining which option is most efficient via short calculations to estimate standard error,
maintain a 50-50 split of steps between reference and target during data collection with
with adjustStepFreqFrequency = false;