Colloids Simulation

Description

This repository contains a Fortran-based Brownian Dynamics simulation. The primary goal of the project is to simulate the behavior of colloidal particles under various forces and stresses using the NVT ensemble and the Ermack & McCammon algorithm. The simulation includes calculations of radial distribution functions and uses the Verlet list for optimizing particle interaction computations.

Contents

• src/: Contains the main Fortran program and subroutines:

  • BD_v07.f90: The main Brownian Dynamics simulation program.
  • GdR.f90: Subroutine for calculating the radial distribution function (RDF) of the particle system (integrated within BD_v07.f90).
  • VERLET.f90: Subroutine for generating the Verlet list to optimize force calculations between particles (integrated within BD_v07.f90).
  • CORRELATION.f90: Subroutine for computing the Mean Squared Displacement (MSD) as a correlation function over time (included in BD_v07.f90).

• data/: Placeholder for data files used in the simulations, such as initial particle configurations.

• docs/: Additional documentation, including the original project report in PDF format.

• LICENSE: License file for the project (LGPL-V3).

Requirements

• Fortran compiler (e.g., gfortran)
• Basic knowledge of running Fortran programs

Installation

1. Clone the repository:

   git clone https://github.com/user/colloids-simulation.git
   cd colloids-simulation

2. Compile the Fortran program:

   gfortran -o brownian_dynamics src/BD_v07.f90

Execution

To execute the Brownian Dynamics simulation, run the compiled program:

./brownian_dynamics

Key Features:

• Verlet List: The program uses the Verlet list for efficient computation of particle interactions.
• Radial Distribution Function (GdR): The program computes the radial distribution function to analyze the spatial distribution of particles.
• Correlation Functions: The program computes the Mean Squared Displacement (MSD) as a correlation function over time using the CORRELATION subroutine.

Simulation Results

Simulation results can be saved and analyzed. You can visualize them using external tools (like gnuplot or matplotlib). The program generates several output files, including:

• MovieBD.xyz: Particle positions.
• EPOT.txt: Potential energy.
• MSD.dat: Mean Squared Displacement (MSD) data.