Accounting for Electronic Coherences Induced by Broadband Pulses by Using Pulse-Independent Trajectories

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Molecular Dynamics

Background:

• Ultrashort laser pulses enable coherent excitation of molecular electronic states.
• Time-resolved experiments monitor ultrafast electron-nuclear dynamics.
• Computational modeling faces challenges with complex coherences and high costs.

Purpose of the Study:

• Develop efficient computational methods for simulating pump-probe experiments.
• Incorporate the effect of pump-generated coherences post-calculation.
• Enable flexible simulations for molecular control studies.

Main Methods:

• Two novel trajectory-surface-hopping approaches presented.
• Methods include pump-generated coherences *a posteriori*.
• Applied to glycine molecules excited by UV pulses.

Main Results:

• Demonstrated effectiveness of the new computational approaches.
• Excellent agreement with methods including coherences from the start.
• Confirmed the significant role of initial coherences in dynamics.

Conclusions:

• Developed accurate and flexible simulation tools for pump-probe spectroscopy.
• New methods reduce computational cost for complex molecular systems.
• Facilitates studies of molecular dynamics and control with broadband lasers.