Dependence of the interatomic potential on distance for the helium-helium, He2, and the lithium-helium, LiHe, dimers (full lines, left scale) along with the probability of finding the constituent atoms at a particular interatomic distance, as given by the square of the ground-state vibrational wave function (dashed lines, right scale). Arrows mark the positions of the minima (PM), mean interatomic separations (MIS), as well as the outer turning points (OTP) in the respective potentials. Note that the positions of the minima of the He2 and LiHe potential-energy curves differ dramatically from the mean interatomic separations. On the scale of the figure, the binding energies of either He2 or LiHe are within the thickness of the horizontal line marking the dissociation limit. The energy of 1 mK is equivalent to 1.381×10-26J.