From the graph, find the maximum P9-O7 distance match the distance O-Mg is equal to 0.7 Angstrom Power and will have a maximum length 0.6 P-O-P bond is broken.
From the graph shows that P9-O7 maximum match O-Mg equal distance distance 0.7 Angstrom, and energy will be maximum at time 0.6 bond P-O-P will break out