Lennard-Jones as a model for argon and test of extended renormalization group calculations

K. G.

Wilson

, , ().

J. A.

White

and

S.

Zhang

, , ().

J. A.

White

and

Sheng

Zhang

, , ().

A.

Michels

,

J. M.

Levelt

, and

W.

DeGraaff

, , ().

Some alternative theoretical approaches for calculating volumetric properties of argon and/or Lennard-Jones fluids throughout a large neighborhood of the critical point have been discussed, with references to earlier work, in

T.

 

Kraska

and

U. K.

 

Deiters

,  , ();

M.

 

Tau

,

A.

 

Parola

,

D.

 

Pini

, and

L.

 

Reatto

,  , ();

L.

 

Reatto

and

A.

 

Parola

,  , ();

Y.

Tang

, , ().

N. F.

Carnahan

and

K. E.

Starling

, , ().

J. A.

Barker

and

D.

Henderson

, , ().

G. J.

Throop

and

R. J.

Bearman

, , ().

F.

Mandel

,

R. J.

Bearman

, and

M. Y.

Bearman

, , ().

J. A.

White

and

S.

Zhang

, , ().

K. G.

Wilson

and

M. E.

Fisher

, , ().

A.

Michels

,

H.

Wijker

, and

H.

Wijker

, , ().

B. E. F.

Fender

and

G. D.

Halsey

, Jr., , ().

A. E.

Sherwood

and

J. M.

Prausnitz

, , ().

Fitting to second virial coefficient data for argon as in Ref. 14, Sherwood, private communication, has found that the overall rms deviations of the calculated second virial coefficients for temperatures in the full range 85–873 K are in the ratio approximately 1/1.7/2.8 for the σ,ε choices in Refs. 14, 13, and 12, respectively. For the three particular temperatures used for Fig. 1, the individual deviations are of roughly equal magnitude for the σ and ε of Refs. 14 and 12, but, at the upper two temperatures, considerably larger for the σ and ε from Ref. 13. [The choices of σ and ε in Refs. 13 and 12 work best in different temperature regimes: deviations from measured second virial coefficients for the σ and ε of Ref. 13 are generally larger than for the other two choices of σ,ε for temperatures above $0.9Tc,$ but smallest for temperatures below 90 K; while the σ and ε of Ref. 12 give generally the smallest deviations for temperatures higher than $Tc$ (≃151 K), but especially large deviations for temperatures below about $0.9Tc.$] I wish to thank A. E. Sherwood for providing me with tabulations of calculated second virial coefficients for the Lennard-Jones potential applied to argon, and their deviations from values derived from experiment, for the temperatures and σ,ε values mentioned above.

B. M.

Axilrod

and

E.

Teller

, , ().