Fig. 2.

Formation of hydroxyglycine. Trajectory snapshots showing, within 50 fs, (A) the bonding of a formamide molecule with a carbon monoxide one, followed by (B) the dissociation of a hydrogen cyanide, (C) leaving behind a formate ion that bonds another formamide (ion) molecule, (D) to yield a hydroxyglycine. Standard color codes are adopted: carbon atoms are displayed in dark gray, nitrogen atoms in blue, oxygen atoms in red, and hydrogen atoms in white. The relevant bond forming and breaking is highlighted by white arrows. The corresponding chemical reactions of A−B and C−D are sketched in between the corresponding configurations. (E) The corresponding metadynamics-determined free energy as function of the C−C distance reaction coordinate is reported.