.. index:: fix meso

fix meso command
================

Syntax
""""""

.. parsed-literal::

   fix ID group-ID meso

* ID, group-ID are documented in :doc:`fix <fix>` command
* meso = style name of this fix command

Examples
""""""""

.. parsed-literal::

   fix 1 all meso

Description
"""""""""""

Perform time integration to update position, velocity, internal energy
and local density for atoms in the group each timestep. This fix is
needed to time-integrate mesoscopic systems where particles carry
internal variables such as SPH or DPDE.

See `this PDF guide <USER/sph/SPH_LAMMPS_userguide.pdf>`_ to using SPH in
LAMMPS.

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
""""""""""""


This fix is part of the USER-SPH package.  It is only enabled if
LAMMPS was built with that package.  See the :ref:`Making LAMMPS <start_3>` section for more info.

Related commands
""""""""""""""""

"fix meso/stationary"

**Default:** none


.. _lws: http://lammps.sandia.gov
.. _ld: Manual.html
.. _lc: Section_commands.html#comm