# Berendsen Barostat¶

## Overview¶

Implements the Berendsen barostat for maintaining pressure at a specified set point pressure P through rescaling of the volume every applyEvery turns.

## Constructor¶

FixPressureBerendsen(state,handle,pressure,period,applyEvery)


Arguments

state
Simulation state to which this fix is applied.
handle
A name for this fix. String type.
groupHandle
The group of atoms to which this fix is applied. String type.
pressure
The set point pressure for the simulation. Double type.
period
The time constant associated with the barostat. Double type.
applyEvery
The number of turns to elapse between applications of this fix. Integer type.

## Python Member Functions¶

setParameters(maxDilation)


Arguments

maxDilation
The maximum factor by which the system volume may be scaled in any given turn. Defaults to 0.00001.

## Examples¶

# create a simulation state to which we will apply the fix
state = State()

# make an instance of the fix; specify pressure of 0.5, period of 10, applyEvery 1
fixPressure = FixPressureBerendsen(state,"npt",0.5,10,1)

# call set parameters to change maxDilation to 0.0001
fixPressure.setParameters(0.0001)

# activate the fix
state.activateFix(fixPressure)