Not in AE, I'm afraid.
Ideally this sort of project would use Massive. If not, you could use Thinking Particles in Cinema4D (or the equivalent in other 3d apps). Particular has no particle collision detection except for the ability to make particles collide on one or two planes; no way to make particles respond with any collision with one another.
- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')
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