“…Thanks to normal form (NF) theories (a classical analog of quantum Van Vleck perturbation theory), it was revealed in classical Hamiltonian systems with many degrees of freedom, 9,10,17,19,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] that one can robustly extract the NHIM, no-return TS, and the stable/unstable invariant manifolds up to a moderately high energy regime above the saddle point energy, even under the existence of chaos arising from nonlinear couplings. The potential of the theories has been demonstrated not only in chemical reactions with 17,22 and without [23][24][25][26][27] time-dependent external field but also in ionization of a hydrogen atom in crossed electric and magnetic fields, [28][29][30] isomerization of clusters, [31][32][33][34][35][36] and the escape of asteroids from Mars 37,38 [Just recently the theory was also generalized to quantum Hamiltonian systems [39][40][41] and dissipative (generalized) Langevin systems.…”