# md_fast

md_fast, a MATLAB code which carries out a molecular dynamics simulation. It is a version of MD that has been revised to take advantage of MATLAB's vector abilities.

The computation involves following the paths of particles which exert a distance-dependent force on each other. The particles are not constrained by any walls; if particles meet, they simply pass through each other.

The problem is treated as a coupled set of differential equations. The system of differential equation is discretized by choosing a discrete time step. Given the position and velocity of each particle at one time step, the algorithm estimates these values at the next time step.

To compute the next position of each particle requires the evaluation of the right hand side of its corresponding differential equation. Since each of these calculations is independent, there is a potential speedup if the program can take advantage of parallel computing.

This version of the program is intended as a starting point; students are asked to examine the program and add the appropriate parallel MATLAB modifications to run it in parallel.

### Usage:

md_fast ( nd, np, step_num )
where
• nd is the spatial dimension, usually 2 or 3.
• np is the number of particles in the system. A typical value might be 1000.
• step_num is the number of time steps, which might be 500 or 1,000.

### Languages:

md_fast is available in a MATLAB version.

### Related Data and Programs:

fft_serial, a MATLAB code which demonstrates the computation of a Fast Fourier Transform, and is intended as a starting point for implementing a parallel version.

heated_plate, a MATLAB code which solves the steady (time independent) heat equation in a 2D rectangular region, and is intended as a starting point for implementing a parallel version.

md, a MATLAB code which carries out a molecular dynamics simulation, intended as a starting point for implementing a parallel version.

prime, a MATLAB code which counts the number of primes between 1 and N, intended as a starting point for the creation of a parallel version.

quad, a MATLAB code which approximates an integral using a quadrature rule, and is intended as a starting point for parallelization exercises.

### Reference:

1. Matthew Allen, Dominic Tildesley,
Computer Simulation of Liquids,
Oxford University Press, 1987,
ISBN: 0198556454,
LC: QC145.2.
2. Peter Arbenz, Wesley Petersen,
Introduction to Parallel Computing - A practical guide with examples in C,
Oxford University Press,
ISBN: 0-19-851576-6,
LC: QA76.58.P47.
3. Rohit Chandra, Leonardo Dagum, Dave Kohr, Dror Maydan, Jeff McDonald, Ramesh Menon,
Parallel Programming in OpenMP,
Morgan Kaufmann, 2001,
ISBN: 1-55860-671-8,
LC: QA76.642.P32.
4. Barbara Chapman, Gabriele Jost, Ruud vanderPas, David Kuck,
Using OpenMP: Portable Shared Memory Parallel Processing,
MIT Press, 2007,
ISBN13: 978-0262533027,
LC: QA76.642.C49.
5. Furio Ercolessi,
A Molecular Dynamics Primer.
6. Philipp Janert,
Gnuplot in Action: Understanding Data with Graphs,
Manning, 2008,
ISBN: 1-933988-39-8.
7. Dennis Rapaport,
An Introduction to Interactive Molecular-Dynamics Simulation,
Computers in Physics,
Volume 11, Number 4, July/August 1997, pages 337-347.
8. Dennis Rapaport,
The Art of Molecular Dynamics Simulation,
Cambridge University Press, 2004,
ISBN: 0521825687.

### Source Code:

Last revised on 17 February 2019.