“…They possess a repulsive core that exhibits a region of softening where the slope changes dramatically. This region can be a shoulder or a ramp [13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32]. Unfortunately, these models, even when successful in showing density anomaly and two liquid phases, fail in providing the connection between the isotropic effective potential and the realistic potential of water.…”