85 lines
1.9 KiB
ReStructuredText
85 lines
1.9 KiB
ReStructuredText
.. index:: bond_style mesocnt
|
|
|
|
bond_style mesocnt command
|
|
===========================
|
|
|
|
Syntax
|
|
""""""
|
|
|
|
.. code-block:: LAMMPS
|
|
|
|
bond_style mesocnt
|
|
|
|
Examples
|
|
""""""""
|
|
|
|
.. code-block:: LAMMPS
|
|
|
|
bond_style mesocnt
|
|
bond_coeff 1 C 10 10 20.0
|
|
bond_coeff 4 custom 800.0 10.0
|
|
|
|
Description
|
|
"""""""""""
|
|
|
|
.. versionadded:: 15Sep2022
|
|
|
|
The *mesocnt* bond style is a wrapper for the :doc:`harmonic
|
|
<bond_harmonic>` style, and uses the potential
|
|
|
|
.. math::
|
|
|
|
E = K (r - r_0)^2
|
|
|
|
where :math:`r_0` is the equilibrium bond distance. Note that the
|
|
usual 1/2 factor is included in :math:`K`. The style implements
|
|
parameterization presets of :math:`K` for mesoscopic simulations of
|
|
carbon nanotubes based on the atomistic simulations of
|
|
:ref:`(Srivastava) <Srivastava_1>`.
|
|
|
|
Other presets can be readily implemented in the future.
|
|
|
|
The following coefficients must be defined for each bond type via the
|
|
:doc:`bond_coeff <bond_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:
|
|
|
|
* preset = *C* or *custom*
|
|
* additional parameters depending on preset
|
|
|
|
Preset *C* is for carbon nanotubes, and the additional parameters are:
|
|
|
|
* chiral index :math:`n` (unitless)
|
|
* chiral index :math:`m` (unitless)
|
|
* :math:`r_0` (distance)
|
|
|
|
Preset *custom* is simply a direct wrapper for the :doc:`harmonic
|
|
<bond_harmonic>` style, and the additional parameters are:
|
|
|
|
* :math:`K` (energy/distance\^2)
|
|
* :math:`r_0` (distance)
|
|
|
|
Restrictions
|
|
""""""""""""
|
|
|
|
This bond style can only be used if LAMMPS was built with the MOLECULE
|
|
and MESONT packages. See the :doc:`Build package <Build_package>`
|
|
page for more info.
|
|
|
|
Related commands
|
|
""""""""""""""""
|
|
|
|
:doc:`bond_coeff <bond_coeff>`, :doc:`delete_bonds <delete_bonds>`
|
|
|
|
Default
|
|
"""""""
|
|
|
|
none
|
|
|
|
----------
|
|
|
|
.. _Srivastava_1:
|
|
|
|
**(Srivastava)** Zhigilei, Wei and Srivastava, Phys. Rev. B 71, 165417
|
|
(2005).
|