One of the CVs used in this work requires the N-H coordination number exclusively from the N atom closest to the C atom from CO 2 . The smooth version of this CV can be computed using Eq. 4, with δ N C a switching function approaching 1 when N is closest to CO 2 C atom, and 0 instead. The functional form of δ N C is given in Eq. 5. The constant λ controls the smoothness of δ N C , and it is here set to 12.