Peng Robinsion EOS,P=[ρRT/(1-bρ)]-[(aα(T)ρ2)/(1+2bρ-b2 ρ2 )]

〖α(T)=[1+(0.37464+1.54226ω-0.26992ω^2)(1-√(T⁄(Tc)))]〗^2, where ω=0.344 for water, a= 2/49, b=3/21 & R=1.

ψ(ρ)=√(2(P-ρcs2 )/(c0 G1)),where cs2=1/3 speed of sound, G1= -1