Computing van der Waals constants from molecular structure

How can van der Waals constants be computed from molecular structure?


Is there software that already does this?


Is there software that can design a molecule with specified van der Waals constants?


This relates to the question
[Fluids with critical point at ordinary temperature and pressure](https://physics.stackexchange.com/questions/268470/fluids-with-critical-point-at-ordinary-temperature-and-pressure)


