Nonadiabatic electron wavepacket states in excited small carbon clusters

Area of Science:

• Quantum Chemistry
• Theoretical Chemistry
• Materials Science

Background:

• Small carbon clusters exhibit complex electronic excited states.
• These states involve quasi-degenerate electronic states and frequent nonadiabatic transitions.

Purpose of the Study:

• To report and characterize a new class of electronic excited states in small carbon clusters.
• To analyze the nonadiabatic interactions and quantum chaotic dynamics within these states.

Main Methods:

• Numerical analysis of geometrical decomposition (collective coordinate analysis) of nonadiabatic interactions.
• Investigation of electron wavepacket dynamics and energy dissipation mechanisms.
• Proposal of an ionization profile from energy natural orbitals (ENOs).

Main Results:

• Identification of complex electronic excited states in carbon clusters, characterized by quantum chaos and diffusion-like electron wavepacket propagation.
• Observation of strong chemical bonds despite significant electronic fluctuations.
• Dissipation of nuclear kinetic energy to the electronic sea via nonadiabatic couplings, leading to "equilibration".
• Long cluster lifetimes against dissociation and ionization despite high electronic state energy.

Conclusions:

• Complex electronic excited states represent a significant finding in the study of small carbon clusters.
• The quantum chaotic dynamics and unique properties of these states offer new insights into electron-nuclear interactions.
• Further research into energy natural orbitals (ENOs) and their dynamics can elucidate ionization processes.