The Casimir effect makes two close metal plates in a vacuum attract.
I was pondering and figured out that two close molecules should experience the same effect, as they are close and between molecules there is nothing. Maybe even stronger as they are usually way closer than metal plates can be.
So, is there any theoretical work on this? Is the Casimir "force" considered one of the van der Waals forces? Am I talking nonsense?
Also, could the attraction between the plates result from van der Waals interactions and not from the quantum field stuff? How is it known that this is not the case?