Figure , Heat transfer between two molecules In a random system, the regular cases are minor. The majority are the deformed cases shown in Fig. , in which the BD plane crosses with the AC plane at an angle. In Case a), the increase of potential is only found in the counter-rotation. In the equidirectional rotation, the potentials keep unchanging. In Case b), L>Le, the potential decreases, whereas, L<Le, the potential increases. In Case c), the potentials of two molecules are constant. Hence, as L>Le, the probability is increase and decrease, whereas, as L>Le, it is , in which the potential increases. That is why the system potential dramatically increases near Tc. Provided that the system is constituted by one kind of molecule and the molecular temperature is constant, the repulsive is the coulomb's force between two nuclei.