Berendsen

class hoomd.md.methods.thermostats.Berendsen(kT, tau)

Bases: Thermostat

The Berendsen thermostat.

Parameters:

• kT (hoomd.variant.variant_like) – Temperature of the simulation. $[\mathrm{energy}]$

• tau (float) – Thermostat time constant. $[\mathrm{time}]$

Berendsen rescales the velocities of all particles on each time step. The rescaling is performed so that the difference in the current temperature from the set point decays exponentially:

$$\frac{dT_\mathrm{cur}}{dt} = \frac{T - T_\mathrm{cur}}{\tau}$$

Attention

Berendsen does NOT sample the correct distribution of kinetic energies.

See also

Berendsen et. al. 1984.

Example:

berendsen = hoomd.md.methods.thermostats.Berendsen(
    kT=1.5,
    tau=simulation.operations.integrator.dt * 10_000,
)
simulation.operations.integrator.methods[0].thermostat = berendsen

kT

Temperature of the simulation. $[energy]$

Examples:

berendsen.kT = 1.0

berendsen.kT = hoomd.variant.Ramp(
    A=1.0, B=2.0, t_start=0, t_ramp=1_000_000
)

Type:

hoomd.variant.variant_like

tau

Time constant of thermostat. $[time]$

Type:

float