Mixed Quantum-Classical Dynamics Using Collective Electronic Variables: A Better Alternative to Electronic Friction...

Area of Science:

• Computational Chemistry
• Surface Science
• Quantum Dynamics

Background:

• Describing nonadiabatic dynamics of molecules on metals is computationally challenging due to numerous electronic states.
• Existing methods like Ehrenfest or friction models have limitations.

Purpose of the Study:

• To introduce a mixed quantum-classical scheme using collective electronic variables.
• To address the computational challenges in modeling nonadiabatic molecular dynamics on metallic surfaces.

Main Methods:

• Developed a novel mixed quantum-classical scheme.
• Introduced collective electronic variables via analytic block-diagonalization of the Hamiltonian.
• Compared the scheme with Ehrenfest and electronic friction models using a 1D adatom model.

Main Results:

• The collective-mode dynamics approach with few variables is robust.
• Accurately describes various scenarios, from insulators to metallic surfaces.
• The friction approach demonstrated unpredictable failures.

Conclusions:

• Collective electronic variables offer a reliable method for nonadiabatic dynamics.
• This scheme provides a more stable and accurate alternative to friction models for surface chemistry simulations.