Page MenuHomec4science
Files F93110681

improper_style.html
No OneTemporary
Actions

File Metadata

Created
Tue, Nov 26, 07:13

improper_style.html
View Options

<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>improper_style command &mdash; LAMMPS documentation</title>
<link rel="stylesheet" href="_static/css/theme.css" type="text/css" />
<link rel="stylesheet" href="_static/sphinxcontrib-images/LightBox2/lightbox2/css/lightbox.css" type="text/css" />
<link rel="top" title="LAMMPS documentation" href="index.html"/>
<link rel="up" title="Commands" href="commands.html"/>
<link rel="next" title="include command" href="include.html"/>
<link rel="prev" title="improper_coeff command" href="improper_coeff.html"/>
<script src="_static/js/modernizr.min.js"></script>
</head>
<body class="wy-body-for-nav" role="document">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-nav-search">
<a href="Manual.html" class="icon icon-home"> LAMMPS
</a>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<p class="caption"><span class="caption-text">User Documentation</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="Section_intro.html">1. Introduction</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_start.html">2. Getting Started</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_commands.html">3. Commands</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_packages.html">4. Packages</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_accelerate.html">5. Accelerating LAMMPS performance</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_howto.html">6. How-to discussions</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_example.html">7. Example problems</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_perf.html">8. Performance &amp; scalability</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_tools.html">9. Additional tools</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_modify.html">10. Modifying &amp; extending LAMMPS</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_python.html">11. Python interface to LAMMPS</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_errors.html">12. Errors</a></li>
<li class="toctree-l1"><a class="reference internal" href="Section_history.html">13. Future and history</a></li>
</ul>
<p class="caption"><span class="caption-text">Index</span></p>
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="tutorials.html">Tutorials</a></li>
<li class="toctree-l1 current"><a class="reference internal" href="commands.html">Commands</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="angle_coeff.html">angle_coeff command</a></li>
<li class="toctree-l2"><a class="reference internal" href="angle_style.html">angle_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="atom_modify.html">atom_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="atom_style.html">atom_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="balance.html">balance command</a></li>
<li class="toctree-l2"><a class="reference internal" href="bond_coeff.html">bond_coeff command</a></li>
<li class="toctree-l2"><a class="reference internal" href="bond_style.html">bond_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="bond_write.html">bond_write command</a></li>
<li class="toctree-l2"><a class="reference internal" href="boundary.html">boundary command</a></li>
<li class="toctree-l2"><a class="reference internal" href="box.html">box command</a></li>
<li class="toctree-l2"><a class="reference internal" href="change_box.html">change_box command</a></li>
<li class="toctree-l2"><a class="reference internal" href="clear.html">clear command</a></li>
<li class="toctree-l2"><a class="reference internal" href="comm_modify.html">comm_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="comm_style.html">comm_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="compute.html">compute command</a></li>
<li class="toctree-l2"><a class="reference internal" href="compute_modify.html">compute_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="create_atoms.html">create_atoms command</a></li>
<li class="toctree-l2"><a class="reference internal" href="create_bonds.html">create_bonds command</a></li>
<li class="toctree-l2"><a class="reference internal" href="create_box.html">create_box command</a></li>
<li class="toctree-l2"><a class="reference internal" href="delete_atoms.html">delete_atoms command</a></li>
<li class="toctree-l2"><a class="reference internal" href="delete_bonds.html">delete_bonds command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dielectric.html">dielectric command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dihedral_coeff.html">dihedral_coeff command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dihedral_style.html">dihedral_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dimension.html">dimension command</a></li>
<li class="toctree-l2"><a class="reference internal" href="displace_atoms.html">displace_atoms command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump.html">dump command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump.html#dump-custom-vtk-command"><code class="docutils literal"><span class="pre">dump</span> <span class="pre">custom/vtk</span></code> command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump.html#dump-h5md-command"><code class="docutils literal"><span class="pre">dump</span> <span class="pre">h5md</span></code> command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump.html#dump-image-command"><code class="docutils literal"><span class="pre">dump</span> <span class="pre">image</span></code> command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump.html#dump-movie-command"><code class="docutils literal"><span class="pre">dump</span> <span class="pre">movie</span></code> command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump.html#dump-molfile-command"><code class="docutils literal"><span class="pre">dump</span> <span class="pre">molfile</span></code> command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump_custom_vtk.html">dump custom/vtk command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump_h5md.html">dump h5md command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump_image.html">dump image command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump_image.html#dump-movie-command">dump movie command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump_modify.html">dump_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump_molfile.html">dump molfile command</a></li>
<li class="toctree-l2"><a class="reference internal" href="echo.html">echo command</a></li>
<li class="toctree-l2"><a class="reference internal" href="fix.html">fix command</a></li>
<li class="toctree-l2"><a class="reference internal" href="fix_modify.html">fix_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="group.html">group command</a></li>
<li class="toctree-l2"><a class="reference internal" href="group2ndx.html">group2ndx command</a></li>
<li class="toctree-l2"><a class="reference internal" href="group2ndx.html#ndx2group-command">ndx2group command</a></li>
<li class="toctree-l2"><a class="reference internal" href="if.html">if command</a></li>
<li class="toctree-l2"><a class="reference internal" href="improper_coeff.html">improper_coeff command</a></li>
<li class="toctree-l2 current"><a class="current reference internal" href="#">improper_style command</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#syntax">Syntax</a></li>
<li class="toctree-l3"><a class="reference internal" href="#examples">Examples</a></li>
<li class="toctree-l3"><a class="reference internal" href="#description">Description</a></li>
<li class="toctree-l3"><a class="reference internal" href="#restrictions">Restrictions</a></li>
<li class="toctree-l3"><a class="reference internal" href="#related-commands">Related commands</a></li>
<li class="toctree-l3"><a class="reference internal" href="#default">Default</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="include.html">include command</a></li>
<li class="toctree-l2"><a class="reference internal" href="info.html">info command</a></li>
<li class="toctree-l2"><a class="reference internal" href="jump.html">jump command</a></li>
<li class="toctree-l2"><a class="reference internal" href="kspace_modify.html">kspace_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="kspace_style.html">kspace_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="label.html">label command</a></li>
<li class="toctree-l2"><a class="reference internal" href="lattice.html">lattice command</a></li>
<li class="toctree-l2"><a class="reference internal" href="log.html">log command</a></li>
<li class="toctree-l2"><a class="reference internal" href="mass.html">mass command</a></li>
<li class="toctree-l2"><a class="reference internal" href="min_modify.html">min_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="min_style.html">min_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="minimize.html">minimize command</a></li>
<li class="toctree-l2"><a class="reference internal" href="molecule.html">molecule command</a></li>
<li class="toctree-l2"><a class="reference internal" href="neb.html">neb command</a></li>
<li class="toctree-l2"><a class="reference internal" href="neigh_modify.html">neigh_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="neighbor.html">neighbor command</a></li>
<li class="toctree-l2"><a class="reference internal" href="newton.html">newton command</a></li>
<li class="toctree-l2"><a class="reference internal" href="next.html">next command</a></li>
<li class="toctree-l2"><a class="reference internal" href="package.html">package command</a></li>
<li class="toctree-l2"><a class="reference internal" href="pair_coeff.html">pair_coeff command</a></li>
<li class="toctree-l2"><a class="reference internal" href="pair_modify.html">pair_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="pair_style.html">pair_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="pair_write.html">pair_write command</a></li>
<li class="toctree-l2"><a class="reference internal" href="partition.html">partition command</a></li>
<li class="toctree-l2"><a class="reference internal" href="prd.html">prd command</a></li>
<li class="toctree-l2"><a class="reference internal" href="print.html">print command</a></li>
<li class="toctree-l2"><a class="reference internal" href="processors.html">processors command</a></li>
<li class="toctree-l2"><a class="reference internal" href="python.html">python command</a></li>
<li class="toctree-l2"><a class="reference internal" href="quit.html">quit command</a></li>
<li class="toctree-l2"><a class="reference internal" href="read_data.html">read_data command</a></li>
<li class="toctree-l2"><a class="reference internal" href="read_dump.html">read_dump command</a></li>
<li class="toctree-l2"><a class="reference internal" href="read_restart.html">read_restart command</a></li>
<li class="toctree-l2"><a class="reference internal" href="region.html">region command</a></li>
<li class="toctree-l2"><a class="reference internal" href="replicate.html">replicate command</a></li>
<li class="toctree-l2"><a class="reference internal" href="rerun.html">rerun command</a></li>
<li class="toctree-l2"><a class="reference internal" href="reset_timestep.html">reset_timestep command</a></li>
<li class="toctree-l2"><a class="reference internal" href="restart.html">restart command</a></li>
<li class="toctree-l2"><a class="reference internal" href="run.html">run command</a></li>
<li class="toctree-l2"><a class="reference internal" href="run_style.html">run_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="set.html">set command</a></li>
<li class="toctree-l2"><a class="reference internal" href="shell.html">shell command</a></li>
<li class="toctree-l2"><a class="reference internal" href="special_bonds.html">special_bonds command</a></li>
<li class="toctree-l2"><a class="reference internal" href="suffix.html">suffix command</a></li>
<li class="toctree-l2"><a class="reference internal" href="tad.html">tad command</a></li>
<li class="toctree-l2"><a class="reference internal" href="temper.html">temper command</a></li>
<li class="toctree-l2"><a class="reference internal" href="thermo.html">thermo command</a></li>
<li class="toctree-l2"><a class="reference internal" href="thermo_modify.html">thermo_modify command</a></li>
<li class="toctree-l2"><a class="reference internal" href="thermo_style.html">thermo_style command</a></li>
<li class="toctree-l2"><a class="reference internal" href="timer.html">timer command</a></li>
<li class="toctree-l2"><a class="reference internal" href="timestep.html">timestep command</a></li>
<li class="toctree-l2"><a class="reference internal" href="uncompute.html">uncompute command</a></li>
<li class="toctree-l2"><a class="reference internal" href="undump.html">undump command</a></li>
<li class="toctree-l2"><a class="reference internal" href="unfix.html">unfix command</a></li>
<li class="toctree-l2"><a class="reference internal" href="units.html">units command</a></li>
<li class="toctree-l2"><a class="reference internal" href="variable.html">variable command</a></li>
<li class="toctree-l2"><a class="reference internal" href="velocity.html">velocity command</a></li>
<li class="toctree-l2"><a class="reference internal" href="write_coeff.html">write_coeff command</a></li>
<li class="toctree-l2"><a class="reference internal" href="write_data.html">write_data command</a></li>
<li class="toctree-l2"><a class="reference internal" href="write_dump.html">write_dump command</a></li>
<li class="toctree-l2"><a class="reference internal" href="write_restart.html">write_restart command</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="fixes.html">Fixes</a></li>
<li class="toctree-l1"><a class="reference internal" href="computes.html">Computes</a></li>
<li class="toctree-l1"><a class="reference internal" href="pairs.html">Pair Styles</a></li>
<li class="toctree-l1"><a class="reference internal" href="bonds.html">Bond Styles</a></li>
<li class="toctree-l1"><a class="reference internal" href="angles.html">Angle Styles</a></li>
<li class="toctree-l1"><a class="reference internal" href="dihedrals.html">Dihedral Styles</a></li>
<li class="toctree-l1"><a class="reference internal" href="impropers.html">Improper Styles</a></li>
</ul>
</div>
&nbsp;
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" role="navigation" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="Manual.html">LAMMPS</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="Manual.html">Docs</a> &raquo;</li>
<li><a href="commands.html">Commands</a> &raquo;</li>
<li>improper_style command</li>
<li class="wy-breadcrumbs-aside">
<a href="http://lammps.sandia.gov">Website</a>
<a href="Section_commands.html#comm">Commands</a>
</li>
</ul>
<hr/>
<div class="rst-footer-buttons" style="margin-bottom: 1em" role="navigation" aria-label="footer navigation">
<a href="include.html" class="btn btn-neutral float-right" title="include command" accesskey="n">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="improper_coeff.html" class="btn btn-neutral" title="improper_coeff command" accesskey="p"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<div class="section" id="improper-style-command">
<span id="index-0"></span><h1>improper_style command</h1>
<div class="section" id="syntax">
<h2>Syntax</h2>
<pre class="literal-block">
improper_style style
</pre>
<ul class="simple">
<li>style = <em>none</em> or <em>hybrid</em> or <em>class2</em> or <em>cvff</em> or <em>harmonic</em></li>
</ul>
</div>
<div class="section" id="examples">
<h2>Examples</h2>
<pre class="literal-block">
improper_style harmonic
improper_style cvff
improper_style hybrid cvff harmonic
</pre>
</div>
<div class="section" id="description">
<h2>Description</h2>
<p>Set the formula(s) LAMMPS uses to compute improper interactions
between quadruplets of atoms, which remain in force for the duration
of the simulation. The list of improper quadruplets is read in by a
<a class="reference internal" href="read_data.html"><span class="doc">read_data</span></a> or <a class="reference internal" href="read_restart.html"><span class="doc">read_restart</span></a> command
from a data or restart file. Note that the ordering of the 4 atoms in
an improper quadruplet determines the the definition of the improper
angle used in the formula for each style. See the doc pages of
individual styles for details.</p>
<p>Hybrid models where impropers are computed using different improper
potentials can be setup using the <em>hybrid</em> improper style.</p>
<p>The coefficients associated with an improper style can be specified in
a data or restart file or via the <a class="reference internal" href="improper_coeff.html"><span class="doc">improper_coeff</span></a>
command.</p>
<p>All improper potentials store their coefficient data in binary restart
files which means improper_style and
<a class="reference internal" href="improper_coeff.html"><span class="doc">improper_coeff</span></a> commands do not need to be
re-specified in an input script that restarts a simulation. See the
<a class="reference internal" href="read_restart.html"><span class="doc">read_restart</span></a> command for details on how to do
this. The one exception is that improper_style <em>hybrid</em> only stores
the list of sub-styles in the restart file; improper coefficients need
to be re-specified.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">When both an improper and pair style is defined, the
<a class="reference internal" href="special_bonds.html"><span class="doc">special_bonds</span></a> command often needs to be used to
turn off (or weight) the pairwise interaction that would otherwise
exist between a group of 4 bonded atoms.</p>
</div>
<hr class="docutils" />
<p>Here is an alphabetic list of improper styles defined in LAMMPS.
Click on the style to display the formula it computes and coefficients
specified by the associated <a class="reference internal" href="improper_coeff.html"><span class="doc">improper_coeff</span></a>
command.</p>
<p>Note that there are also additional improper styles submitted by users
which are included in the LAMMPS distribution. The list of these with
links to the individual styles are given in the improper section of
<a class="reference internal" href="Section_commands.html#cmd-5"><span class="std std-ref">this page</span></a>.</p>
<ul class="simple">
<li><a class="reference internal" href="improper_none.html"><span class="doc">improper_style none</span></a> - turn off improper interactions</li>
<li><a class="reference internal" href="improper_zero.html"><span class="doc">improper_style zero</span></a> - topology but no interactions</li>
<li><a class="reference internal" href="improper_hybrid.html"><span class="doc">improper_style hybrid</span></a> - define multiple styles of improper interactions</li>
<li><a class="reference internal" href="improper_class2.html"><span class="doc">improper_style class2</span></a> - COMPASS (class 2) improper</li>
<li><a class="reference internal" href="improper_cvff.html"><span class="doc">improper_style cvff</span></a> - CVFF improper</li>
<li><a class="reference internal" href="improper_harmonic.html"><span class="doc">improper_style harmonic</span></a> - harmonic improper</li>
<li><a class="reference internal" href="improper_umbrella.html"><span class="doc">improper_style umbrella</span></a> - DREIDING improper</li>
</ul>
</div>
<hr class="docutils" />
<div class="section" id="restrictions">
<h2>Restrictions</h2>
<p>Improper styles can only be set for atom_style choices that allow
impropers to be defined.</p>
<p>Most improper styles are part of the MOLECULE package. They are only
enabled if LAMMPS was built with that package. See the <a class="reference internal" href="Section_start.html#start-3"><span class="std std-ref">Making LAMMPS</span></a> section for more info on packages.
The doc pages for individual improper potentials tell if it is part of
a package.</p>
</div>
<div class="section" id="related-commands">
<h2>Related commands</h2>
<p><a class="reference internal" href="improper_coeff.html"><span class="doc">improper_coeff</span></a></p>
</div>
<div class="section" id="default">
<h2>Default</h2>
<pre class="literal-block">
improper_style none
</pre>
</div>
</div>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="include.html" class="btn btn-neutral float-right" title="include command" accesskey="n">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="improper_coeff.html" class="btn btn-neutral" title="improper_coeff command" accesskey="p"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<p>
&copy; Copyright 2013 Sandia Corporation.
</p>
</div>
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT:'./',
VERSION:'',
COLLAPSE_INDEX:false,
FILE_SUFFIX:'.html',
HAS_SOURCE: true
};
</script>
<script type="text/javascript" src="_static/jquery.js"></script>
<script type="text/javascript" src="_static/underscore.js"></script>
<script type="text/javascript" src="_static/doctools.js"></script>
<script type="text/javascript" src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2/js/jquery-1.11.0.min.js"></script>
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2/js/lightbox.min.js"></script>
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2-customize/jquery-noconflict.js"></script>
<script type="text/javascript" src="_static/js/theme.js"></script>
<script type="text/javascript">
jQuery(function () {
SphinxRtdTheme.StickyNav.enable();
});
</script>
</body>
</html>

Event Timeline

c4science · Help