A modified generalized Langevin oscillator model for activated gas-surface reactions

Area of Science:

• Physical Chemistry
• Surface Science
• Computational Chemistry

Background:

• Surface motion significantly influences gas-surface reactions, necessitating accurate theoretical models.
• Existing models often struggle to adequately capture complex lattice effects in gas-surface interactions.
• Understanding molecule-surface coupling is crucial for predicting reaction dynamics, especially for activated dissociation.

Purpose of the Study:

• To develop a simplified yet accurate model for describing lattice effects in gas-surface reactions.
• To incorporate molecule-surface coupling into the Generalized Langevin Oscillator (GLO) model.
• To validate the modified model's performance using the CHD3+Ni(111) system.

Main Methods:

• Modification of the Generalized Langevin Oscillator (GLO) model to include a coupling potential dependent on surface coordinates.
• Introduction of a mechanic coupling parameter to scale the surface oscillator's mass for improved energy transfer description.
• Validation against benchmark data from *ab initio* molecular dynamics simulations for the CHD3+Ni(111) system.

Main Results:

• The modified GLO (MGLO) model accurately predicts dissociative sticking coefficients for reactive scattering.
• The MGLO model significantly improves the description of molecule-surface energy transfer in nonreactive scattering.
• MGLO model results show remarkable agreement with *ab initio* molecular dynamics benchmark data.

Conclusions:

• The MGLO model offers a computationally efficient and accurate approach to simulating gas-surface reactions with strong molecule-surface couplings.
• The MGLO model successfully captures essential dynamics for activated dissociation and energy transfer processes.
• This simplified MGLO model is a promising tool for studying highly activated gas-surface reactions on metal surfaces.