Tejero and Cuesta hard disk equation of state

The Tejero and Cuesta hard disk equation of state is given by (Ref. 1 Eq. 3.10)

$Z(\eta )={\frac {1+\sum _{n=1}^{6}C_{n}\eta ^{n}}{(1-\eta )^{2}}}$

where

$C_{1}$	0
$C_{2}$	0.128018
$C_{3}$	0.0018188
$C_{4}$	-0.72553
$C_{5}$	2.52783
$C_{6}$	-2.4945

$\eta$ is the packing fraction and Z is the compressibility factor.

References

1. C. F. Tejero and J. A. Cuesta "Hard-sphere and hard-disk freezing from the differential formulation of the generalized effective liquid approximation", Physical Review E 47 pp. 490-495 (1993)