fix langevin/mlml command

Syntax

fix ID group-ID langevin/mlml Tstart Tstop damp seed mlmix_region keyword values ...

  • ID, group-ID are documented in fix command

  • langevin = style name of this fix command

  • Tstart,Tstop = desired temperature at start/end of run (temperature units)

  • Tstart can be a variable (see below)

  • damp = damping parameter (time units)

  • seed = random number seed to use for white noise (positive integer)

  • mlmix_region = region ID of the mlml region to apply the fix to

  • zero or more keyword/value pairs may be appended

  • keyword = angmom or gjf or omega or scale or tally or zero

    angmom value = no or factor
  no = do not thermostat rotational degrees of freedom via the angular momentum
  factor = do thermostat rotational degrees of freedom via the angular momentum and apply numeric scale factor as discussed below
gjf value = no or vfull or vhalf
  no = use standard formulation
  vfull = use Gronbech-Jensen/Farago formulation
  vhalf = use 2GJ formulation
omega value = no or yes
  no = do not thermostat rotational degrees of freedom via the angular velocity
  yes = do thermostat rotational degrees of freedom via the angular velocity
scale values = type ratio
  type = atom type (1-N)
  ratio = factor by which to scale the damping coefficient
tally value = no or yes
  no = do not tally the energy added/subtracted to atoms
  yes = do tally the energy added/subtracted to atoms
zero value = no or yes
  no = do not set total random force to zero
  yes = set total random force to zero

Examples

fix mlml_langevin all langevin/mlml 900 900 2.0 12345 2

Description

Apply a Langevin thermostat, as described in the main LAMMPS documentation, with the difference that this fix applies the thermostat to a specific region of the simulation domain designated by the mlmix package. Which region the thermostat is applied to is determined by the mlmix_region argument. The mlmix_region argument must either be 1 or 2.

Restrictions

To use this fix, the i2_potential and d2_eval property/atoms must be defined. The group used with this command must be all.

Default

The option defaults are angmom = no, omega = no, scale = 1.0 for all types, tally = no, zero = no, gjf = no.