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Manuscript Title: Programs for the molecular dynamics simulation of liquids: I. Spherical molecules with short-ranged interactions.
Authors: D. Fincham
Program title: MDATOM
Catalogue identifier: ABVO_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 21(1980)247
Programming language: Fortran.
Computer: CDC 7600.
Operating system: SCOPE 2.1.5.
RAM: 7K words
Word size: 60
Peripherals: disc.
Keywords: Solid state physics, Other, Simulation liquid, Lennard-jones fluid, Molecular dynamics.
Classification: 7.7.

Nature of problem:
Study of the thermodynamic, structural and dynamic properties of liquids or solids.

Solution method:
A system of a few hundred molecules is simulated. The equations of motion are solved in a series of time steps, at each of which the force on each molecule, due to its interaction with the other molecules in the system, is found. Periodic boundary conditions are applied to make the system pseudo infinite. When the system is in thermal equilibrium thermodynamic measurements are made by averaging over time. The radial distribution function can be found, and also the mean square displacement of the molecules as a function of the time. Information such as coordinates, forces and velocities at successive timesteps may be saved for further analysis.

The present program is suitable only for a few hundred molecules with interactions described by central short-ranged pair potentials.

Running time:
The execution time on the CDC 7600 per timestep of the simulation is 0.037 s with 108 particles, and 0.209 s with 256 particles. The complete test job, with compilation and execution for a total of 7000 timesteps, for 108 particles, took 260 s.