mirror of https://github.com/lammps/lammps.git
74 lines
1.8 KiB
Plaintext
74 lines
1.8 KiB
Plaintext
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.. index:: box
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box command
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===========
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Syntax
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""""""
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.. parsed-literal::
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box keyword value ...
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* one or more keyword/value pairs may be appended
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* keyword = *tilt*
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.. parsed-literal::
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*tilt* value = *small* or *large*
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Examples
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""""""""
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.. parsed-literal::
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box tilt large
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box tilt small
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Description
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"""""""""""
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Set attributes of the simulation box.
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For triclinic (non-orthogonal) simulation boxes, the *tilt* keyword
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allows simulation domains to be created with arbitrary tilt factors,
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e.g. via the :doc:`create_box <create_box>` or
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:doc:`read_data <read_data>` commands. Tilt factors determine how
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skewed the triclinic box is; see :ref:`this section <howto_12>` of the manual for a discussion of
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triclinic boxes in LAMMPS.
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LAMMPS normally requires that no tilt factor can skew the box more
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than half the distance of the parallel box length, which is the 1st
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dimension in the tilt factor (x for xz). If *tilt* is set to
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*small*\ , which is the default, then an error will be
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generated if a box is created which exceeds this limit. If *tilt*
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is set to *large*\ , then no limit is enforced. You can create
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a box with any tilt factors you wish.
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Note that if a simulation box has a large tilt factor, LAMMPS will run
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less efficiently, due to the large volume of communication needed to
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acquire ghost atoms around a processor's irregular-shaped sub-domain.
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For extreme values of tilt, LAMMPS may also lose atoms and generate an
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error.
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Restrictions
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""""""""""""
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This command cannot be used after the simulation box is defined by a
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:doc:`read_data <read_data>` or :doc:`create_box <create_box>` command or
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:doc:`read_restart <read_restart>` command.
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**Related commands:** none
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Default
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"""""""
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The default value is tilt = small.
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.. _lws: http://lammps.sandia.gov
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.. _ld: Manual.html
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.. _lc: Section_commands.html#comm
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