I am taking a second course in Quantum Mechanics right now, and one thing is bugging me... The wave function gives us the probability distribution of a particle being in some position. But which part of particle is it talking about? The center of the particle? But then how can you give a wave function for something more complex like a molecule? Shouldn't your wave function then kinda give you a probability distribution of the molecule occupying a set of points in space or something? My guess was that you can't even define a wave function for a complex molecule like that, but they did Double Slit experiments with bucky-balls and observed interference patterns, so it must have something... And defining it to be just a sum of all the wave functions of things that it's made up of doesn't make too much sense either ...?