Pair stress approximation

Pair stress approximation for hard particles is given by (Eq. 3.18)

$\rho B_2=\frac{q}{(1+q{)}^{B_3}}$

where $q=P/k_{B}T\rho -1$, $B_2$ is the second virial coefficient and $B_3$ is the third virial coefficient.

See also

• Scaled-particle theory
• BBGKY hierarchy