forked from lijiext/lammps
278 lines
11 KiB
HTML
278 lines
11 KiB
HTML
|
|
|
|
<!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_coeff command — 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"/>
|
|
|
|
|
|
<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">
|
|
|
|
|
|
|
|
<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 & 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 & 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>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</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> »</li>
|
|
|
|
<li>improper_coeff 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>
|
|
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
|
|
<div itemprop="articleBody">
|
|
|
|
<div class="section" id="improper-coeff-command">
|
|
<span id="index-0"></span><h1>improper_coeff command<a class="headerlink" href="#improper-coeff-command" title="Permalink to this headline">¶</a></h1>
|
|
<div class="section" id="syntax">
|
|
<h2>Syntax<a class="headerlink" href="#syntax" title="Permalink to this headline">¶</a></h2>
|
|
<div class="highlight-python"><div class="highlight"><pre>improper_coeff N args
|
|
</pre></div>
|
|
</div>
|
|
<ul class="simple">
|
|
<li>N = improper type (see asterisk form below)</li>
|
|
<li>args = coefficients for one or more improper types</li>
|
|
</ul>
|
|
</div>
|
|
<div class="section" id="examples">
|
|
<h2>Examples<a class="headerlink" href="#examples" title="Permalink to this headline">¶</a></h2>
|
|
<div class="highlight-python"><div class="highlight"><pre>improper_coeff 1 300.0 0.0
|
|
improper_coeff * 80.2 -1 2
|
|
improper_coeff *4 80.2 -1 2
|
|
</pre></div>
|
|
</div>
|
|
</div>
|
|
<div class="section" id="description">
|
|
<h2>Description<a class="headerlink" href="#description" title="Permalink to this headline">¶</a></h2>
|
|
<p>Specify the improper force field coefficients for one or more improper
|
|
types. The number and meaning of the coefficients depends on the
|
|
improper style. Improper coefficients can also be set in the data
|
|
file read by the <a class="reference internal" href="read_data.html"><em>read_data</em></a> command or in a restart
|
|
file.</p>
|
|
<p>N can be specified in one of two ways. An explicit numeric value can
|
|
be used, as in the 1st example above. Or a wild-card asterisk can be
|
|
used to set the coefficients for multiple improper types. This takes
|
|
the form “*” or “<em>n” or “n</em>” or “m*n”. If N = the number of improper
|
|
types, then an asterisk with no numeric values means all types from 1
|
|
to N. A leading asterisk means all types from 1 to n (inclusive). A
|
|
trailing asterisk means all types from n to N (inclusive). A middle
|
|
asterisk means all types from m to n (inclusive).</p>
|
|
<p>Note that using an improper_coeff command can override a previous
|
|
setting for the same improper type. For example, these commands set
|
|
the coeffs for all improper types, then overwrite the coeffs for just
|
|
improper type 2:</p>
|
|
<div class="highlight-python"><div class="highlight"><pre>improper_coeff * 300.0 0.0
|
|
improper_coeff 2 50.0 0.0
|
|
</pre></div>
|
|
</div>
|
|
<p>A line in a data file that specifies improper coefficients uses the
|
|
exact same format as the arguments of the improper_coeff command in an
|
|
input script, except that wild-card asterisks should not be used since
|
|
coefficients for all N types must be listed in the file. For example,
|
|
under the “Improper Coeffs” section of a data file, the line that
|
|
corresponds to the 1st example above would be listed as</p>
|
|
<div class="highlight-python"><div class="highlight"><pre>1 300.0 0.0
|
|
</pre></div>
|
|
</div>
|
|
<p>The <a class="reference internal" href="improper_class2.html"><em>improper_style class2</em></a> is an exception to
|
|
this rule, in that an additional argument is used in the input script
|
|
to allow specification of the cross-term coefficients. See its doc
|
|
page for details.</p>
|
|
<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=""><em>improper_coeff</em></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>this page</span></a>.</p>
|
|
<ul class="simple">
|
|
<li><a class="reference internal" href="improper_none.html"><em>improper_style none</em></a> - turn off improper interactions</li>
|
|
<li><a class="reference internal" href="improper_hybrid.html"><em>improper_style hybrid</em></a> - define multiple styles of improper interactions</li>
|
|
<li><a class="reference internal" href="improper_class2.html"><em>improper_style class2</em></a> - COMPASS (class 2) improper</li>
|
|
<li><a class="reference internal" href="improper_cvff.html"><em>improper_style cvff</em></a> - CVFF improper</li>
|
|
<li><a class="reference internal" href="improper_harmonic.html"><em>improper_style harmonic</em></a> - harmonic improper</li>
|
|
<li><a class="reference internal" href="improper_umbrella.html"><em>improper_style umbrella</em></a> - DREIDING improper</li>
|
|
</ul>
|
|
</div>
|
|
<hr class="docutils" />
|
|
<div class="section" id="restrictions">
|
|
<h2>Restrictions<a class="headerlink" href="#restrictions" title="Permalink to this headline">¶</a></h2>
|
|
<p>This command must come after the simulation box is defined by a
|
|
<a class="reference internal" href="read_data.html"><em>read_data</em></a>, <a class="reference internal" href="read_restart.html"><em>read_restart</em></a>, or
|
|
<a class="reference internal" href="create_box.html"><em>create_box</em></a> command.</p>
|
|
<p>An improper style must be defined before any improper coefficients are
|
|
set, either in the input script or in a data file.</p>
|
|
</div>
|
|
<div class="section" id="related-commands">
|
|
<h2>Related commands<a class="headerlink" href="#related-commands" title="Permalink to this headline">¶</a></h2>
|
|
<p><a class="reference internal" href="improper_style.html"><em>improper_style</em></a></p>
|
|
<p><strong>Default:</strong> none</p>
|
|
</div>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
</div>
|
|
<footer>
|
|
|
|
|
|
<hr/>
|
|
|
|
<div role="contentinfo">
|
|
<p>
|
|
© 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> |