132 lines
4.4 KiB
ReStructuredText
132 lines
4.4 KiB
ReStructuredText
.. index:: pair_style brownian
|
|
.. index:: pair_style brownian/omp
|
|
.. index:: pair_style brownian/poly
|
|
.. index:: pair_style brownian/poly/omp
|
|
|
|
pair_style brownian command
|
|
===========================
|
|
|
|
Accelerator Variants: *brownian/omp*
|
|
|
|
pair_style brownian/poly command
|
|
================================
|
|
|
|
Accelerator Variants: *brownian/poly/omp*
|
|
|
|
Syntax
|
|
""""""
|
|
|
|
.. code-block:: LAMMPS
|
|
|
|
pair_style style mu flaglog flagfld cutinner cutoff t_target seed flagHI flagVF
|
|
|
|
* style = *brownian* or *brownian/poly*
|
|
* mu = dynamic viscosity (dynamic viscosity units)
|
|
* flaglog = 0/1 log terms in the lubrication approximation on/off
|
|
* flagfld = 0/1 to include/exclude Fast Lubrication Dynamics effects
|
|
* cutinner = inner cutoff distance (distance units)
|
|
* cutoff = outer cutoff for interactions (distance units)
|
|
* t_target = target temp of the system (temperature units)
|
|
* seed = seed for the random number generator (positive integer)
|
|
* flagHI (optional) = 0/1 to include/exclude 1/r hydrodynamic interactions
|
|
* flagVF (optional) = 0/1 to include/exclude volume fraction corrections in the long-range isotropic terms
|
|
|
|
Examples
|
|
""""""""
|
|
|
|
.. code-block:: LAMMPS
|
|
|
|
pair_style brownian 1.5 1 1 2.01 2.5 2.0 5878567 # (assuming radius = 1)
|
|
pair_coeff 1 1 2.05 2.8
|
|
pair_coeff * *
|
|
|
|
Description
|
|
"""""""""""
|
|
|
|
Styles *brownian* and *brownian/poly* compute Brownian forces and
|
|
torques on finite-size spherical particles. The former requires
|
|
monodisperse spherical particles; the latter allows for polydisperse
|
|
spherical particles.
|
|
|
|
These pair styles are designed to be used with either the :doc:`pair_style lubricate <pair_lubricate>` or :doc:`pair_style lubricateU <pair_lubricateU>` commands to provide thermostatting
|
|
when dissipative lubrication forces are acting. Thus the parameters
|
|
*mu*, *flaglog*, *flagfld*, *cutinner*, and *cutoff* should be
|
|
specified consistent with the settings in the lubrication pair styles.
|
|
For details, refer to either of the lubrication pair styles.
|
|
|
|
The *t_target* setting is used to specify the target temperature of
|
|
the system. The random number *seed* is used to generate random
|
|
numbers for the thermostatting procedure.
|
|
|
|
The *flagHI* and *flagVF* settings are optional. Neither should be
|
|
used, or both must be defined.
|
|
|
|
----------
|
|
|
|
The following coefficients must be defined for each pair of atoms
|
|
types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
|
|
above, or in the data file or restart files read by the
|
|
:doc:`read_data <read_data>` or :doc:`read_restart <read_restart>`
|
|
commands, or by mixing as described below:
|
|
|
|
* cutinner (distance units)
|
|
* cutoff (distance units)
|
|
|
|
The two coefficients are optional. If neither is specified, the two
|
|
cutoffs specified in the pair_style command are used. Otherwise both
|
|
must be specified.
|
|
|
|
----------
|
|
|
|
.. include:: accel_styles.rst
|
|
|
|
----------
|
|
|
|
Mixing, shift, table, tail correction, restart, rRESPA info
|
|
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
|
|
|
|
For atom type pairs I,J and I != J, the two cutoff distances for this
|
|
pair style can be mixed. The default mix value is *geometric*\ . See
|
|
the "pair_modify" command for details.
|
|
|
|
This pair style does not support the :doc:`pair_modify <pair_modify>`
|
|
shift option for the energy of the pair interaction.
|
|
|
|
The :doc:`pair_modify <pair_modify>` table option is not relevant
|
|
for this pair style.
|
|
|
|
This pair style does not support the :doc:`pair_modify <pair_modify>`
|
|
tail option for adding long-range tail corrections to energy and
|
|
pressure.
|
|
|
|
This pair style writes its information to :doc:`binary restart files <restart>`, so pair_style and pair_coeff commands do not need
|
|
to be specified in an input script that reads a restart file.
|
|
|
|
This pair style can only be used via the *pair* keyword of the
|
|
:doc:`run_style respa <run_style>` command. It does not support the
|
|
*inner*, *middle*, *outer* keywords.
|
|
|
|
----------
|
|
|
|
Restrictions
|
|
""""""""""""
|
|
|
|
These styles are part of the COLLOID package. They are only enabled
|
|
if LAMMPS was built with that package. See the :doc:`Build package <Build_package>` page for more info.
|
|
|
|
Only spherical monodisperse particles are allowed for pair_style
|
|
brownian.
|
|
|
|
Only spherical particles are allowed for pair_style brownian/poly.
|
|
|
|
Related commands
|
|
""""""""""""""""
|
|
|
|
:doc:`pair_coeff <pair_coeff>`, :doc:`pair_style lubricate <pair_lubricate>`, :doc:`pair_style lubricateU <pair_lubricateU>`
|
|
|
|
Default
|
|
"""""""
|
|
|
|
The default settings for the optional args are flagHI = 1 and flagVF =
|
|
1.
|