I'd like to recommend Avogadro which is FOSS. One can drag and drop atoms to create any molecule. With annealing the atoms the will arrange themselves in a phys

I'd like to recommend Avogadro which is FOSS. One can drag and drop atoms to create any molecule. With annealing the atoms the will arrange themselves in a physically realistic position. https://avogadro.cc https://avogadro.cc https://avogadro.cc/wiki/Screenshots https://avogadro.cc/wiki/Screenshots Here's a screencast of building a caffeine molecule with Avogadro: https://www.youtube.com/watch?v=HrbahnykY6g https://www.youtube.com/watch?v=HrbahnykY6g