Thermodynamics basic state equation

Saturation and cubic basic equiations for pure susbtances

This zip contains the following equations for pure susbtances thermodynamics properties estimation:
> Cubic state equations
- Van der Waals
- Redlich-Kwong-Soave
- Redlich-Kwong
- Peng-Robinson

> Saturation properties correlations
- Wagner
- Clapeyron (and its simplication, Clasius-Clapeyron)
- Rackett (saturated liquid volume calculation)

This zip also includes a modification for state cubic equation done by Soave, to give a better estimate for saturation properties using experimental data.