Fig. 3

Energy profile (red) for each frame (1–16) of the QM/MM calculation with two Mg²⁺ ions; the values for energy are on the y1 axis. Frame numbers (1–16) represent steps on the reaction path, in which 1 is reactant and 16 is product. Values for distances between atoms Cyt6 03′—P (3DR7) (green) and water 1863 OH2-P (3DR7) (blue) are marked on the y2 axis