Points on the Zeno curve Z have a compressibility factor of unity Z = p / ( ρ ρ T ) = 1 . The Zeno curve originates at the Boyle temperature T B = 3.417927982 ε ε k B − − 1 , surrounds the critical point, and has a slope of unity in the low temperature limit. Points on the Boyle curve B have d Z d ( 1 / ρ ρ ) | T = 0 . The Boyle curve originates with the Zeno curve at the Boyle temperature, faintly surrounds the critical point, and ends on the vapor pressure curve. Points on the Charles curve (a.k.a. Joule-Thomson inversion curve) have d Z d T | p = 0 and more importantly d T d p | h = 0 , i.e. no temperature change upon isenthalpic throttling. It originates at T = 6.430798418 ε ε k B − − 1 in the ideal gas limit, crosses the Zeno curve, and terminates on the vapor pressure curve. Points on the Amagat curve A have d Z d T | ρ ρ = 0 . It also starts in the ideal gas limit at T = 25.15242837 ε ε k B − − 1 , surrounds the critical point and the other three characteristic curves and passes into the solid phase region. A comprehensive discussion of the characteristic curves of the Lennard-Jones potential is given by Stephan and Deiters.