Dynamics of FHCl Including Two Bidirectional Dissociation Channels: Comparative Study Using Quantum Nuclear...

Area of Science:

• Physical Chemistry
• Quantum Dynamics
• Chemical Physics

Background:

• Investigating the dissociation dynamics of neutral FHCl from its charge transfer excited state.
• Understanding the competing electron-transfer (ET) and proton-transfer (PT) dissociation channels.

Purpose of the Study:

• To elucidate the quantum features governing the dissociation dynamics of FHCl.
• To confirm previously observed quantum phenomena, such as the dominance of PT over ET and a characteristic time gap.
• To provide classical interpretations for these quantum dynamics using semiclassical methods.

Main Methods:

• Quantum dynamics simulations employing nuclear wavepacket propagation.
• Semiclassical dynamics simulations utilizing trajectory surface hopping.
• Electronic state energy calculations using the MS-CASPT2(17,11)/aug-cc-pVTZ method.

Main Results:

• Confirmed the dominance of proton-transfer (PT) over electron-transfer (ET) in FHCl dissociation.
• Verified a time gap of approximately 80 fs between the onset of PT and ET processes.
• Identified the crucial roles of nonadiabatic region locations and angular motion in controlling dissociation pathways.

Conclusions:

• The quantum dynamics of FHCl dissociation exhibit distinct features not predicted by classical intuition.
• Semiclassical dynamics provide a framework for understanding the origins of these quantum effects.
• The interplay between electronic states and nuclear motion dictates the observed dissociation behavior.