Photo-induced 1,3-cyclohexadiene ring opening reaction: Ab initio on-the-fly nonadiabatic molecular dynamics simulation

Ultrafast Photoinduced Dynamics of 1,3-Cyclohexadiene Using XMS-CASPT2 Surface Hopping

“…38,39 Such a large QY, which however could have been affected by a rather poor time resolution of early diffraction experiments, was in striking contrast to the results of electronic structure calculations, which rather consistently predicted a yield similar to the one shown for the reaction in solution. 14,[21][22][23][25][26][27][28][29][30] Two later experiments provided an indirect evidence of a non-unit QY in the gas phase (50% 40 and an upper bound of 73% 41 ) and finally Adachi et al estimated it as low as 30% by fitting the observed differential photoelectron spectra (averaged over the time range of 510 − 990 fs after initial excitation) into the estimated ones based on He(I) photoelectron spectra. 11 The nature of the observed branching ratio is not clear either and has been attributed to the local PES topology around the S 1 /S 0 CoIn and its location on a hypersurface, 14,22 extended crossing seam, 19 sufficient wavepacket momentum, 26 gained along the stretching carbon-carbon bond 30,42 or more generally along the bond-alternating coordinate.…”

“…[5][6][7][8][9][10][11] Experimental findings have been supported by theoretical calculations, including study of potential energy surface (PES) critical points, 7,[12][13][14][15][16][17][18][19] restricted-dimensional quantum dynamical, [20][21][22][23] and fulldimensional mixed quantum-classical trajectory-based simulations. [24][25][26][27][28][29][30] Until recently, the explicit evolution of geometry following photoexcitation could be obtained only from potential surfaces derived from electronic structure calculations; recent advances in ultrafast X-ray sources with high intensity and electron diffraction techniques have allowed for the first direct insights into the sub-picosecond imaging of CHD photodissociation. [31][32][33] The first X-ray spectroscopic study to directly reveal the valence electronic structure of the transient pericyclic minimum predicted by Lugt and Oosterhoff has also been performed.…”

Benchmark Performance of Global Switching versus Local Switching for Trajectory Surface Hopping Molecular Dynamics Simulation: Cis↔Trans Azobenzene Photoisomerization

“…[27] along an on-thefly trajectory.T his new globals witching algorithm was successfully applied to photoisomerization dynamics in relatively large organic molecules, and simulated quantum yields and lifetimes are in good agreement with experimentalr esults. [27][28][29][30][31] Thenew GS algorithm was shown to be computationally powerful for performing ab initio on-the-flyt rajectory surfaceh opping molecular dynamics simulations within four singlet low-lying electronic states coupled with complicated conicali ntersection networks for cis-trans azobenzene photoisomerization. [28]…”

Effects of probe energy and competing pathways on time-resolved photoelectron spectroscopy: the ring-opening of 1,3-cyclohexadiene

“…[14][15][16] The reaction has been studied extensively using a wide array of time-resolved techniques in solution and gas phase, including resonance Raman spectroscopy, [17][18][19] transient absorption, 12,20,21 photoelectron spectroscopy, [22][23][24] and dissociative intense-field ionisation. [25][26][27] Computational studies include electronic structure calculations 16,[28][29][30][31][32][33] and dynamics, [34][35][36][37][38][39][40][41][42] as well as joint theoretical and experimental work. 23,[43][44][45] It is notable that despite such extensive study, the understanding of the reaction is not complete.…”