Prediction through quantum dynamics simulations: Photo-excited cyclobutanone

Area of Science:

• Computational Chemistry
• Quantum Dynamics
• Photochemistry

Background:

• Non-adiabatic dynamics simulations are crucial for understanding photo-excited molecular systems.
• Assessing the predictive power of these simulations is essential for advancing chemical research.

Purpose of the Study:

• To perform quantum dynamics simulations of cyclobutanone after photo-excitation.
• To evaluate the accuracy of simulation methods by comparing with future experimental data.

Main Methods:

• Utilized grid-based multi-configuration time-dependent Hartree (MCTDH) and direct dynamics variational multi-configuration Gaussian (DD-vMCG) methods.
• Employed a parameterized vibronic coupling model Hamiltonian and on-the-fly potential energy surface generation.

Main Results:

• Simulations reveal rapid relaxation from the S2 to S1 state in cyclobutanone within 500 fs.
• A small population transfers to the S0 state, with no significant population transfer to triplet states observed.
• Predicted GUED signals primarily relate to C-O stretch and C-C-O axis elongation.

Conclusions:

• Quantum dynamics simulations provide insights into cyclobutanone's non-adiabatic behavior.
• The study lays the groundwork for validating simulation predictive power against experimental gas-phase ultrafast electron diffraction (GUED) data.