Glotzer:Binary Mixture Module
From NSDL Materials Digital Library Wiki
This simulation consists of a binary-mixture of particles that interact via the Lennard-Jones Potential and the Weeks-Chandler-Andersen Potential . The system runs NVT Molecular Dynamics using the Berendsen Thermostat. The number of particles, number density and temperature are all user-modifiable variables.
- Particle-particle interactions between like particles are modeled using the Lennard-Jones potential. Interactions are truncated and shifted at the standard 2.5σ, where σ, the particle diameter, is set to 1.
- Particle-particle interactions between dislike particles are modeled using the Weeks-Chandler-Andersen potential. Interactions are truncated at 21 / 6σ, where σ, the particle diameter, is set to 1.
- This simulation uses Brownian Dynamics where the equations of motion are integrated using the Velocity Verlet integration scheme.
- Temperature is kept constant by the use of the Berendsen Thermostat .
- A brute force neighbor list routine is used to calculate particle-particle interactions, thus simulation is most suited for smaller system sizes < ~1000;
- periodic boundary conditionts are utilized.
- Instructions for installing modules can be found on the Module Installation page.
A variety of system parameters can be modified as shown in the schematic below. To run at this statepoint, simply press the Run Simulation button. After pressing Run Simulation a visualizer window with the simulation will appear, as shown below. Note that the number of timesteps completed are displaced in the bottom left corner. Name of Run will correspond to the directory name where data will be saved. The code will crash if there are spaces or odd characters.
The simulation can be terminated from within the visualizer window by pressing "escape", "q" or select "Quit" from the application menu. Additional functionality of the visualizer can be found on the Visualizer Controls page.
The phase behavior of this system will be a function of both temperature and Number density.
- For Number of Particles = 512, Number density=0.9, Temperature = 0.6, hide one species, describe the formation of the domains as a function of time. Make sure you run for ~30,000 timesteps. Repeat for Temperature =0.2 (run for ~50000). Was is the impact of temperature? How does these compare to the following animations?
- Simulation snapshots of the evolution of a 2-D binary phase separating system using the Cahn-Hilliard Model, Full MatDL Record
- Simulation snapshot of a phase separated binary mixture using [[softmatter:Dissipative Particle Dynamics| Dissipative Particle Dynamics], Full MatDL Record
- James K. Hoffer and Dipen N. Sinha Dynamics of binary phase separation in liquid 3-4He mixtures, Phys. Rev. A 33, 1918 - 1939 (1986)
- John W. Cahn Phase Separation by Spinodal Decomposition in Isotropic Systems JOURNAL OF CHEMICAL PHYSICS 42 (1): 93-& 1965
- E. Sander and T. Wanner. Monte Carlo simulations for spinodal decomposition. Journal of Statistical Physics, 95(5-6):925-948, 1999.
- Spinodal Decomposition Animations
- softmatter:Basic Dynamical Simulation Methodology
- softmatter:Molecular Dynamics Simulation (MD)
- softmatter:Simulation Variables/Units
- softmatter:Periodic boundary conditions
- softmatter:Pair potential
- softmatter:The Lennard-Jones Potential
- softmatter:Weeks-Chandler-Andersen Potential
- Glotzer:Visualizer Controls