LAMMPS WWW Site - LAMMPS Documentation - LAMMPS Commands

fix temp/rescale command

Syntax:

fix ID group-ID temp/rescale N Tstart Tstop window fraction 

Examples:

fix 3 flow temp/rescale 100 1.0 1.1 0.02 0.5 

Description:

Reset the temperature of a group of atoms by explicitly rescaling their velocities.

Rescaling is performed every N timesteps. The target temperature is a ramped value between the Tstart and Tstop temperatures at the beginning and end of the run. Rescaling is only performed if the difference between the current and desired temperatures is greater than the window value. The amount of rescaling that is applied is a fraction (from 0.0 to 1.0) of the difference between the actual and desired temperature. E.g. if fraction = 1.0, the temperature is reset to exactly the desired value.

The way that temperature is computed by this fix can be changed by using the fix_modify command.

A temp/rescale fix does not update the coordinates of its atoms. It is normally used with a fix of style nve that does that. A temp/rescale fix should not normally be used on atoms that also have their temperature controlled by another fix - e.g. a nvt or langevin fix.

This fix supports the fix_modify options for thermo and energy. The former will print the contribution the fix makes to the energy of the system when thermodynamics is printed. The latter will add this contribution to the total potential energy (PotEng) so that energy conservation can be monitored.

Restrictions: none

Related commands:

fix langevin, fix nvt, fix_modify

Default: none