Coulomb Explosion Imaging for the Visualization of a Conical Intersection

Area of Science:

• Chemical Physics
• Molecular Dynamics
• Quantum Chemistry

Background:

• Conical intersections are critical points in molecular systems where non-adiabatic transitions occur.
• Understanding these intersections is key to elucidating reaction mechanisms and dynamics.
• Methyl iodide serves as a model system for studying these phenomena due to its dissociative surfaces.

Purpose of the Study:

• To introduce and validate Coulomb explosion imaging as a direct method for mapping conical intersections.
• To investigate the non-adiabatic coupling between dissociative surfaces in methyl iodide.
• To visualize molecular dynamics through conical intersections.

Main Methods:

• Utilizing intense, short near-infrared laser pulses for multiple ionization of methyl iodide.
• Employing on-the-fly multidimensional trajectory calculations with surface hopping.
• Incorporating perturbation theory and spin-orbit coupling in theoretical models.

Main Results:

• Direct mapping of conical intersections in methyl iodide was achieved using Coulomb explosion imaging.
• The study visualized the molecular dynamics traversing the conical intersection.
• Theoretical calculations were successfully compared with experimental observations.

Conclusions:

• Coulomb explosion imaging is a viable technique for directly observing conical intersections.
• The study provides insights into the non-adiabatic dynamics of methyl iodide.
• The method's potential and limitations for studying molecular systems were discussed.