# Parrinello-Rahman barostat

**Parrinello-Rahman barostat**

The Parrinello-Rahman barostat is a method commonly used in molecular simulation to maintain constant pressure in a system. It is based on adjusting the volume of the system to control the internal pressure.

The Parrinello-Rahman barostat algorithm is based on a constrained molecular dynamics approach, which uses a constraint matrix to anisotropically adjust the volume of the system. This means that the dimensions of each direction can be modified independently according to the desired pressures.

The Parrinello-Rahman barostat makes it possible to simulate systems under constant pressure conditions, which is essential for studying phase transitions, elastic properties of materials, molecular interactions under pressure, and so on. By controlling the volume of the system in each direction independently, this method offers great flexibility for reproducing specific pressure conditions in molecular simulations.

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## Monte Carlo implementation[edit]

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## References[edit]

- ↑ M. Parrinello and A. Rahman "Crystal Structure and Pair Potentials: A Molecular-Dynamics Study", Physical Review Letters
**45**pp. 1196-1199 (1980) - ↑ M. Parrinello and A. Rahman "Polymorphic transitions in single crystals: A new molecular dynamics method", Journal of Applied Physics
**52**pp. 7182- (1981) - ↑ M. Parrinello and A. Rahman "Strain fluctuations and elastic constants", Journal of Chemical Physics
**76**pp. 2662- (1982) - ↑ Reza Najafabadi and Sidney Yip "Observation of finite-temperature bain transformation (f.c.c. → b.c.c.) in Monte Carlo simulation of iron", Scripta Metallurgica
**17**pp. 1199-1204 (1983) - ↑ S. Yashonath and C. N. R. Rao "A Monte Carlo study of crystal structure transformations", Molecular Physics
**54**pp. 245-251 (1985)