Nonclassical critical indices in the statistical theory of liquids and equations of state with regular and scaling components

Nonclassical critical indices γ = 9/8 and β = 3/8 obtained in works using the statistical theory of liquids are used to approximate data on the isothermal compressibility of ⁴He and SF₆ on critical isochores and binodals, and on the shape of a binodal. The ratio of asymptotic compressibility coefficients Γ ₀ ⁺ /Γ ₀ ^? on critical isochores and binodals is determined from experiments using statistical theory and it is shown that Γ ₀ ⁺ /Γ ₀ ^? coincides with the magnitude of this ratio for linear scaling model with γ = 9/8 and β = 3/8 indices. Highly accurate P-ρ-T data on ⁴He and SF₆ are approximated at these values of the indices using new combined equations of state that include regular and scaling components. The advantage of describing of P-ρ-T data in this manner, compared to describing them with the same equations of state using the critical indices of the three-dimensional Ising model, is demonstrated.