Gas blending using real gases
This CGI script computes instructions to create nitrox mixes. It does take into account a real gas equation of state, but not the van der Waals equation. Rather it uses the same polynomial model as [Subsurface]https://subsurface/subsurface-divelog. This grew out of a discussion on [ScubaBoard]https://scubaboard.com/community/threads/gas-blender-toolkit-wrong-calculation.614075/
You can see it in action at https://thetheoreticaldiver.org/rch-cgi-bin/blender.pl .
Let me know if you want me to extend it to trimix blending.