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)

Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle Z(\eta )={\frac {1+\sum _{n=1}^{6}C_{n}\eta ^{n}}{(1-\eta )^{2}}}}

where

$C_{1}$	0
Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle C_{2}}	0.128018
$C_{3}$	0.0018188
$C_{4}$	-0.72553
Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle 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)