I was once taught that we can calculate a small but non-zero probability for "quantum leaps" for things like atoms. I have tried to review this question within the context of gas molecules and for solids, but alas, I suspect my proficiency ends with very simple models. So first is this correct: In principle, we can calculate a non-zero probability that for any atom having a reasonably well defined position, a chance still exists of finding this atom at some distant location; e.g. 1:10^50 of finding the atom 1 KM away from the classical position. If this is true, can we estimate the real probability for such events for atoms found in gases and solids? For example, is there any way to estimate the chances that a carbon atom in my desk exists at the moon for a moment?