A MASH simulation of the photoexcited dynamics of cyclobutanone
The Journal of Chemical Physics(2024)
摘要
In response to a community prediction challenge, we simulate the nonadiabatic
dynamics of cyclobutanone using the mapping approach to surface hopping (MASH).
We consider the first 500 fs of relaxation following photo-excitation to the S2
state and predict the corresponding time-resolved electron-diffraction signal
that will be measured by the planned experiment. 397 ab-initio trajectories
were obtained on the fly with state-averaged complete active space
self-consistent field (SA-CASSCF) using a (12,11) active space. To obtain an
estimate of the potential systematic error 198 of the trajectories were
calculated using an aug-cc-pVDZ basis set and 199 with a 6-31+G* basis set.
MASH is a recently proposed independent trajectory method for simulating
nonadiabatic dynamics, originally derived for two-state problems. As there are
three relevant electronic states in this system, we used a newly developed
multi-state generalisation of MASH for the simulation: the uncoupled spheres
multi-state MASH method (unSMASH). This study therefore serves both as an
investigation of the photo-dissociation dynamics of cyclobutanone, and also as
a demonstration of the applicability of unSMASH to ab-initio simulations. In
line with previous experimental studies, we observe that the simulated dynamics
is dominated by three sets of dissociation products, C3H6+CO, C2H4+C2H2O and
C2H4+CH2+CO, and we interpret our predicted electron-diffraction signal in
terms of the key features of the associated dissociation pathways.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要