The exponential terms in the last two equations correct the third virial coefficient so that the isotherms in the liquid phase can be represented correctly. The exponential term converges rapidly as ρ increases, and if only the first two terms in its Taylor expansion series are taken, 1 − − γ γ ρ ρ 2 , and multiplied with 1 + γ γ ρ ρ 2 , the result is 1 − − γ γ 2 ρ ρ 4 , which contributes a c / R T 3 term to the third virial coefficient, and one term to the eighth virial coefficient, which can be ignored.