The Vega equation of state for hard (biaxial) ellipsoids is given by:
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.
References
- Carlos Vega "Virial coefficients and equation of state of hard ellipsoids", Molecular Physics 92 pp. 651-665 (1997)