Overall, the ELF analysis of the basin polarization is consistent with the reaction energetics and highlights the distinct influence of Mg²⁺ and Mn²⁺ on the active site's electric field and its implications for reaction kinetics. Furthermore, basins with the nucleotide binding metal shows consistent populations with the three triphosphate non-bridging oxygens, with the basin with the -oxygen increasing with approaching transition state. This might indicate the stabilizing electric field provided by the nucleotide binding metal with developing charges in the active site. Details about the populations of important basins along the reaction path, as well as specific basins related to reactant, transition state and product a are shown in SI Tables S2-S5. Overall, the changes seen in the noncovalent and covalent interactions show higher facilitation of the reaction in the Mn 2+ system as compared to Mg 2+ . Along with this, the protein environment is seen to stabilize the active site of the TS and product of the system with Mn 2+ ions more as compared to Mg 2+ ions. It is also determined that there is higher anti-correlated motion between the thumb and the fingers in the system with Mn 2+ ions (the motion necessary for DNA extension) as compared to the Mg 2+ ions. Overall, these factors together might explain the lower energy barrier and reaction energy of the system with Mn 2+ ions, which is consistent with experimental results.