File:Mpemba HB model.gif

English: O:H–O bond short-range interactions and the O:H–O (denoted as dL and dH) cooperative relaxation dynamics. dH0 and dL0 are the respective references at 4 1C. Indicated are the van der Waals like (vdW approaches the nonbonding interaction) interaction (EL B 0.1 eV) of the O:H nonbond (left-handed side), the exchange interaction (EH B4.0 eV) of the H–O bond (right-handed side), and the Coulomb repulsion between electron pairs (paring green dots) on oxygen ions. A combination of these interactions and the specific heat disparity between the O:H and the H–O bond dislocate O atoms in the same direction by different amounts under cooling. The relaxation proceeds along the O:H–O bond potentials with H atoms (in grey) being the coordination origin under heating (red line linked spheres, denoted hot) or cooling (blue line linked spheres, denoted cold). Springs of different diameters represent the strengths of the respective interactions.