# Vega equation of state for hard ellipsoids

The **Vega** equation of state for an isotropic fluid of hard (biaxial) ellipsoids is given by
^{[1]}
(Eq. 20):

where is the compressibility factor and is the volume fraction, given by where is the number density. The virial coefficients are given by the fits

and

where

- ,

and

where is the volume, , the surface area, and the mean radius of curvature. These can be calculated using this Mathematica notebook file for calculating the surface area and mean radius of curvature of an ellipsoid. For see the page "Second virial coefficient".

## References[edit]

**Related reading**