fix accelerate/cos command
Syntax
fix ID group-ID accelerate value
ID, group-ID are documented in fix command
accelerate/cos = style name of this fix command
value = amplitude of acceleration (in unit of velocity/time)
Examples
fix 1 all accelerate/cos 2.0e-7
Description
Give each atom a acceleration in x-direction based on its z coordinate. The acceleration is a periodic function along the z-direction:
where
The generated velocity amplitude
and it can be obtained from ensemble average of the velocity profile:
where
The velocity amplitude
In order to get meaningful results, the group ID of this fix should be all.
Restart, fix_modify, output, run start/stop, minimize info
No information about this fix is written to binary restart files. None of the fix_modify options are relevant to this fix. No global or per-atom quantities are stored by this fix for access by various output commands. No parameter of this fix can be used with the start/stop keywords of the run command.
This fix is not invoked during energy minimization.
Restrictions
This fix is part of the MISC package. It is only enabled if LAMMPS was built with that package. See the Build package page for more info.
Since this fix depends on the
Default
none
(Hess) Hess, B. Journal of Chemical Physics 2002, 116 (1), 209–217.