forked from lijiext/lammps
92 lines
2.3 KiB
Plaintext
92 lines
2.3 KiB
Plaintext
.. index:: dihedral_style fourier
|
|
|
|
dihedral_style fourier command
|
|
==============================
|
|
|
|
dihedral_style fourier/omp command
|
|
==================================
|
|
|
|
Syntax
|
|
""""""
|
|
|
|
.. parsed-literal::
|
|
|
|
dihedral_style fourier
|
|
|
|
Examples
|
|
""""""""
|
|
|
|
.. parsed-literal::
|
|
|
|
dihedral_style fourier
|
|
dihedral_coeff 1 3 -0.846200 3 0.0 7.578800 1 0 0.138000 2 -180.0
|
|
|
|
Description
|
|
"""""""""""
|
|
|
|
The *fourier* dihedral style uses the potential:
|
|
|
|
.. image:: Eqs/dihedral_fourier.jpg
|
|
:align: center
|
|
|
|
The following coefficients must be defined for each dihedral type via the
|
|
:doc:`dihedral_coeff <dihedral_coeff>` command as in the example above, or in
|
|
the data file or restart files read by the :doc:`read_data <read_data>`
|
|
or :doc:`read_restart <read_restart>` commands:
|
|
|
|
* m (integer >=1)
|
|
* K1 (energy)
|
|
* n1 (integer >= 0)
|
|
* d1 (degrees)
|
|
* ....
|
|
* Km (energy)
|
|
* nm (integer >= 0)
|
|
* dm (degrees)
|
|
|
|
|
|
----------
|
|
|
|
|
|
Styles with a *cuda*, *gpu*, *intel*, *kk*, *omp*, or *opt* suffix are
|
|
functionally the same as the corresponding style without the suffix.
|
|
They have been optimized to run faster, depending on your available
|
|
hardware, as discussed in :doc:`Section_accelerate <Section_accelerate>`
|
|
of the manual. The accelerated styles take the same arguments and
|
|
should produce the same results, except for round-off and precision
|
|
issues.
|
|
|
|
These accelerated styles are part of the USER-CUDA, GPU, USER-INTEL,
|
|
KOKKOS, USER-OMP and OPT packages, respectively. They are only
|
|
enabled if LAMMPS was built with those packages. See the :ref:`Making LAMMPS <start_3>` section for more info.
|
|
|
|
You can specify the accelerated styles explicitly in your input script
|
|
by including their suffix, or you can use the :ref:`-suffix command-line switch <start_7>` when you invoke LAMMPS, or you can
|
|
use the :doc:`suffix <suffix>` command in your input script.
|
|
|
|
See :doc:`Section_accelerate <Section_accelerate>` of the manual for
|
|
more instructions on how to use the accelerated styles effectively.
|
|
|
|
|
|
----------
|
|
|
|
|
|
Restrictions
|
|
""""""""""""
|
|
|
|
|
|
This angle style can only be used if LAMMPS was built with the
|
|
USER_MISC package. See the :ref:`Making LAMMPS <start_3>`
|
|
section for more info on packages.
|
|
|
|
Related commands
|
|
""""""""""""""""
|
|
|
|
:doc:`dihedral_coeff <dihedral_coeff>`
|
|
|
|
**Default:** none
|
|
|
|
|
|
.. _lws: http://lammps.sandia.gov
|
|
.. _ld: Manual.html
|
|
.. _lc: Section_commands.html#comm
|