forked from lijiext/lammps
73 lines
1.8 KiB
Plaintext
73 lines
1.8 KiB
Plaintext
.. index:: fix oneway
|
|
|
|
fix oneway command
|
|
==================
|
|
|
|
Syntax
|
|
""""""
|
|
|
|
.. parsed-literal::
|
|
|
|
fix ID group-ID oneway N region-ID direction
|
|
|
|
* ID, group-ID are documented in :doc:`fix <fix>` command
|
|
* oneway = style name of this fix command
|
|
* N = apply this fix every this many timesteps
|
|
* region-ID = ID of region where fix is active
|
|
* direction = *x* or *-x* or *y* or *-y* or *z* or *-z* = coordinate and direction of the oneway constraint
|
|
|
|
|
|
Examples
|
|
""""""""
|
|
|
|
.. parsed-literal::
|
|
|
|
fix ions oneway 10 semi -x
|
|
fix all oneway 1 left -z
|
|
fix all oneway 1 right z
|
|
|
|
Description
|
|
"""""""""""
|
|
|
|
Enforce that particles in the group and in a given region can only
|
|
move in one direction. This is done by reversing a particle's
|
|
velocity component, if it has the wrong sign in the specified
|
|
dimension. The effect is that the particle moves in one direction
|
|
only.
|
|
|
|
This can be used, for example, as a simple model of a semi-permeable
|
|
membrane, or as an implementation of Maxwell's demon.
|
|
|
|
|
|
----------
|
|
|
|
|
|
Restart, fix_modify, output, run start/stop, minimize info
|
|
""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
|
|
|
|
No information about this fix is written to :doc:`binary restart files <restart>`. None of the :doc:`fix_modify <fix_modify>` options
|
|
are relevant to this fix. No global or per-atom quantities are stored
|
|
by this fix for access by various :ref:`output commands <howto_15>`. No parameter of this fix can
|
|
be used with the *start/stop* keywords of the :doc:`run <run>` command.
|
|
This fix is not invoked during :doc:`energy minimization <minimize>`.
|
|
|
|
Restrictions
|
|
""""""""""""
|
|
none
|
|
|
|
Related commands
|
|
""""""""""""""""
|
|
|
|
:doc:`fix wall/reflect <fix_wall_reflect>` command
|
|
|
|
**Default:** none
|
|
|
|
|
|
----------
|
|
|
|
|
|
|
|
.. _lws: http://lammps.sandia.gov
|
|
.. _ld: Manual.html
|
|
.. _lc: Section_commands.html#comm
|