Surface hopping molecular dynamics simulation of ultrafast methyl iodide photodissociation mapped by Coulomb explosion imaging

Abstract

We present a highly efficient method to directly simulate the photodissociation followed by Coulomb explosion of methyl iodide. In order to achieve statistical reliability, more than 40,000 trajectories are calculated on accurate potential energy surfaces of both the neutral molecule and the doubly charged cation. Non-adiabatic effects during photodissociation are treated using a Landau-Zener surface hopping algorithm. The simulation is performed analogous to a recent pump-probe experiment using coincident ion momentum imaging [Ziaee \textit{et al., Phys. Chem. Chem. Phys.} 2023, \textbf{25}, 9999]. At large pump-probe delays, the simulated delay-dependent kinetic energy release signals show overall good agreement with the experiment, with two major dissociation channels leading to $\text{I}{(}^2{\text{P}}_{3/2})$ and ${\text{I}}^{\ast }{(}^2{\text{P}}_{1/2})$ products. At short pump-probe delays, the simulated kinetic energy release shows a clear bifurcation near 12 fs, owing to non-adiabatic transitions through a conical intersection. The developed method is particularly suitable and efficient in simulating processes that highly rely on statistics or for identifying rare reaction channels.

10 pages, 7 figures

References in corpus (6)

• Cold molecules: Progress in Quantum Engineering of Chemistry and Quantum Matter
• Landau-Zener type surface hopping algorithms
• Probing the UV-Induced Photodissociation of CH${}_{\text{3}}$I and C${}_{\text{6}}$H${}_{\text{3}}$F${}_{\text{2}}$I with Femtosecond Time-Resolved Coulomb Explosion Imaging at FLASH
• Gas-phase structural isomer identification by Coulomb explosion of aligned molecules
• Differentiating Three-Dimensional Molecular Structures using Laser-induced Coulomb Explosion Imaging
• Effective Control of Cold Collisions with Radio Frequency Fields

Cited by in corpus (3)

• Ultrafast photodissociation dynamics of dichloromethane on three-dimensional potential energy surfaces and its Coulomb explosion signature
• Modeling the time-resolved Coulomb explosion imaging of halomethane photodissociation with \textit{ab initio} potential energy curves
• Ground and low-lying excited state potential energy surfaces of diiodomethane in four dimensions