Fig. 13.
β-alanine intramolecular condensation reaction approximate transition states from NEB calculations using 20 replicas. Four calculations with different force constant k (kcal•mol−1• Å−2): yellow, pathway 1, k=10, mass-weight; green, pathway 2, k=100, mass-weight; blue, pathway 3, k=10, additional weight on migration hydrogen; red, pathway 4, k=100, additional weight on migration hydrogen; gray: the TS obtained from QM calculation.