The EDC analysis was carried out using QMAnalysis, a locally developed Python program. For each analysis, it only requires: (a) the Q-Chem checkpoint files for the two end structures (reactant/TS, TS/product, reactant/MECP, or MECP/product); and (b) the pathway file (in xyz format) in between. The QMAnalysis program can be accessed at , which is being further developed. The checkpoint and pathway files can also be found in this GitHub repository.