Reaction pathways of alanine dipeptide isomerization using RPATH/restraint method. The kang for the pathway curvature controlling is 100, 1000, 10000 and 20000, for pathways 1~4, respectively. For all the calculations, krms is 100000, and hydrogens are excluded from mass-weighted RMSD measurement. (force constant unit: kcal•mol−1• Å−2)