Computer simulation techniques

"In those pieces of apparatus [computing machines] I see not only devices to make the forces of nature serviceable in new ways, no, I view them with much greater respect; I dare say that I see in them the true devices for unveiling the essence of things"

Ludwig Eduard Boltzmann "The Second Law of the Mechanical Theory of Heat" (1886)

Computer simulations are used to obtain quantitative results, under various thermodynamic conditions, for realistic models which are parametrised to study a specific atomic or molecular system with a certain degree of realism, or force fields, which consist of transferable parameters for molecular sub-units, usually at the atomistic level. Force fields are designed to be applicable to a variety of molecular systems, in particular for flexible molecules. Computer simulations are also used to perform "computer experiments" on idealised models in order to test theories with a view to arriving at a better understanding of the underlying physics of a system.

The two predominant computer simulation techniques used in the study of soft condensed matter are:

• Molecular dynamics

and

• Monte Carlo

For a list of some of the computer programs available see:

• Materials modelling and computer simulation codes

Material common to both techniques

• Coarse graining
• Computation of phase equilibria
• Configuration analysis
• Constrained cell method
• Dissipative particle dynamics
• Electrostatics
• Ergodic hypothesis
• Expanded ensemble method
• Finite size scaling
• Force fields
• Gibbs-Duhem integration
• Hybrid Monte Carlo
• Iterative Boltzmann inversion
• Models
• Multicanonical ensemble
• Neighbour lists
• Path integrals
• Periodic boundary conditions
• Self-referential method
• Smooth Particle methods
• Statistical-temperature simulation algorithm
• Synthetic method
• Tempering methods
• Test area method
• Test volume method
• Thermostats
• Wandering interface method
• Widom test-particle method

Interesting reading

• W. W. Wood "Early history of computer simulations in statistical mechanics" in "Molecular-dynamics simulation of statistical-mechanical systems" (Eds. Giovanni Ciccotti and William G. Hoover) pp. 3-14 Società Italiana di Fisica (1986)
• Daan Frenkel and Jean-Pierre Hansen "Understanding liquids: a computer game?", Physics World 9 pp. 35–42 (April 1996)
• Wm. G. Hoover "50 Years of Computer Simulation -- A Personal View", arXiv:0812.2086v2 (2008)
• Wilfred F. van Gunsteren, and Alan E. Mark "Validation of molecular dynamics simulation", Journal of Chemical Physics 108 pp. 6109-6116 (1998)
• Richard P. Feynman "Simulating Physics With Computers", International Journal of Theoretical Physics 21 pp. 467-488 (1982)
• Michael P. Allen and David Quigley "Some comments on Monte Carlo and molecular dynamics methods", Molecular Physics 111 pp. 3442-3447 (2013)