Pair forces shape the Joule-Thomson curve

Move the slider from an attractive r-6 tail to a repulsive r-12 core. The right panel recomputes the reduced virial estimate muJTCp = T* dB/dT* - B.

50% repulsive r^-12 coefficient = 1.00, r^-6 coefficient = 1.00 U*(r*) = 4[1.00/r*^12 - 1.00/r*^6]
Pair potential versus reduced distance Generalized Lennard-Jones pair potential as the repulsive and attractive weights change.
Joule-Thomson coefficient times heat capacity versus reduced temperature Reduced virial estimate for the Joule-Thomson coefficient times heat capacity.