The density gradient term in the free-energy expression for a fluid can, as previously shown, be corrected so that the effect of this term on the correlation length parallels the effect of the other terms. It is shown that this same correction improves the values of the critical exponents when...

The simplified renormalization theory has been applied to fluids and generalized so that it can be used elsewhere than on the critical isochore. A general expression for the correlation has been found, and applied to the critical isotherm to get the critical exponent δ. The equation of state is...