Reactive multi-particle collision dynamics with reactive boundary conditions.

Area of Science:

• Computational physics
• Chemical kinetics
• Physical chemistry

Background:

• Modeling reaction-diffusion systems with reactive boundaries is crucial for understanding complex chemical and biological processes.
• Existing particle-based methods often struggle to maintain accurate diffusion coefficients and handle reactive boundaries efficiently.

Purpose of the Study:

• To extend the off-lattice reactive multi-particle collision (RMPC) dynamics to accurately model reaction-diffusion systems with reactive boundary conditions.
• To ensure the precise maintenance of particle diffusion coefficients throughout simulations.
• To incorporate partial adsorption phenomena at reactive boundaries within the RMPC framework.

Main Methods:

• The study utilizes an off-lattice particle-based method, reactive multi-particle collision (RMPC) dynamics.
• Bath particles are introduced to maintain the diffusion coefficient of the main particles.
• A novel approach, analogous to Brownian Dynamics, is employed to model partial adsorption at reactive boundaries.

Main Results:

• The extended RMPC method successfully models reaction-diffusion systems with reactive boundaries.
• The approach maintains the a priori diffusion coefficient of particles.
• Simulations show very good agreement with the analytical solutions of corresponding partial differential equations.
• The method demonstrates conservation of mass, energy, and momentum.

Conclusions:

• The enhanced RMPC method provides an accurate and computationally efficient approach for simulating reaction-diffusion systems with reactive boundaries.
• This method offers advantages over other molecular-based techniques due to its computational cost and conservation properties.
• The successful validation across three test systems highlights its robustness and applicability.