Averaged over the QM/DMD ensembles energies (ZPE-corrected), and structural parameters (in Å) of the stationary points along the methyl transfer path, for the Mg(II), Ca(II), Fe(II), and Fe(III) forms of COMT, with the catechol substrate, and the Mg(II) form with the inhibitor.

aDistance between the oxygen atom of catechol and the closest hydrogen atoms on the side chain of Lys144, (see Scheme S2). bDistance between the oxygen atom of catechol and the carbon atom on the migrating methyl group. cDistance between the sulfur atom of SAM and the carbon atom on the migrating methyl group. dStandard deviations are reported in parantheses.