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>compute force/tally 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>compute force/tally 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="compute-force-tally-command">
|
|
<span id="index-0"></span><h1>compute force/tally command</h1>
|
|
</div>
|
|
<div class="section" id="compute-heat-flux-tally-command">
|
|
<h1>compute heat/flux/tally command</h1>
|
|
</div>
|
|
<div class="section" id="compute-pe-tally-command">
|
|
<h1>compute pe/tally command</h1>
|
|
</div>
|
|
<div class="section" id="compute-pe-mol-tally-command">
|
|
<h1>compute pe/mol/tally command</h1>
|
|
</div>
|
|
<div class="section" id="compute-stress-tally-command">
|
|
<h1>compute stress/tally command</h1>
|
|
<div class="section" id="syntax">
|
|
<h2>Syntax</h2>
|
|
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">compute</span> <span class="n">ID</span> <span class="n">group</span><span class="o">-</span><span class="n">ID</span> <span class="n">style</span> <span class="n">group2</span><span class="o">-</span><span class="n">ID</span>
|
|
</pre></div>
|
|
</div>
|
|
<ul class="simple">
|
|
<li>ID, group-ID are documented in <a class="reference internal" href="compute.html"><span class="doc">compute</span></a> command</li>
|
|
<li>style = <em>force/tally</em> or <em>pe/tally</em> or <em>pe/mol/tally</em> or <em>stress/tally</em></li>
|
|
<li>group2-ID = group ID of second (or same) group</li>
|
|
</ul>
|
|
</div>
|
|
<div class="section" id="examples">
|
|
<h2>Examples</h2>
|
|
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">compute</span> <span class="mi">1</span> <span class="n">lower</span> <span class="n">force</span><span class="o">/</span><span class="n">tally</span> <span class="n">upper</span>
|
|
<span class="n">compute</span> <span class="mi">1</span> <span class="n">left</span> <span class="n">pe</span><span class="o">/</span><span class="n">tally</span> <span class="n">right</span>
|
|
<span class="n">compute</span> <span class="mi">1</span> <span class="n">lower</span> <span class="n">stress</span><span class="o">/</span><span class="n">tally</span> <span class="n">lower</span>
|
|
</pre></div>
|
|
</div>
|
|
</div>
|
|
<div class="section" id="description">
|
|
<h2>Description</h2>
|
|
<p>Define a computation that calculates properties between two groups of
|
|
atoms by accumulating them from pairwise non-bonded computations. The
|
|
two groups can be the same. This is similar to <a class="reference internal" href="compute_group_group.html"><span class="doc">compute group/group</span></a> only that the data is
|
|
accumulated directly during the non-bonded force computation. The
|
|
computes <em>force/tally</em>, <em>pe/tally</em>, <em>stress/tally</em>, and
|
|
<em>heat/flux/tally</em> are primarily provided as example how to program
|
|
additional, more sophisticated computes using the tally mechanism.</p>
|
|
<hr class="docutils" />
|
|
<p>The pairwise contributions are computing via a callback that the
|
|
compute registers with the non-bonded pairwise force computation.
|
|
This limits the use to systems that have no bonds, no Kspace, and no
|
|
manybody interactions. On the other hand, the computation does not
|
|
have to compute forces or energies a second time and thus can be much
|
|
more efficient. The callback mechanism allows to write more complex
|
|
pairwise property computations.</p>
|
|
<hr class="docutils" />
|
|
<p><strong>Output info:</strong></p>
|
|
<p>Compute <em>pe/tally</em> calculates a global scalar (the energy) and a per
|
|
atom scalar (the contributions of the single atom to the global
|
|
scalar). Compute <em>pe/mol/tally</em> calculates a global 4-element vector
|
|
containing (in this order): <em>evdwl</em> and <em>ecoul</em> for intramolecular pairs
|
|
and <em>evdwl</em> and <em>ecoul</em> for intermolecular pairs. Since molecules are
|
|
identified my their molecule IDs, the partitioning does not have to be
|
|
related to molecules, but the energies are tallied into the respective
|
|
slots depending on whether the molecule IDs of a pair are the same or
|
|
different. Compute <em>force/tally</em> calculates a global scalar (the force
|
|
magnitude) and a per atom 3-element vector (force contribution from
|
|
each atom). Compute <em>stress/tally</em> calculates a global scalar
|
|
(average of the diagonal elements of the stress tensor) and a per atom
|
|
vector (the 6 elements of stress tensor contributions from the
|
|
individual atom).</p>
|
|
<p>Both the scalar and vector values calculated by this compute are
|
|
“extensive”.</p>
|
|
</div>
|
|
<div class="section" id="restrictions">
|
|
<h2>Restrictions</h2>
|
|
<p>This compute is part of the USER-TALLY package. It is 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.</p>
|
|
<p>Not all pair styles can be evaluated in a pairwise mode as required by
|
|
this compute. For example, 3-body and other many-body potentials,
|
|
such as <a class="reference internal" href="pair_tersoff.html"><span class="doc">Tersoff</span></a> and
|
|
<a class="reference internal" href="pair_sw.html"><span class="doc">Stillinger-Weber</span></a> cannot be used. <a class="reference internal" href="pair_eam.html"><span class="doc">EAM</span></a>
|
|
potentials only include the pair potential portion of the EAM
|
|
interaction when used by this compute, not the embedding term. Also
|
|
bonded or Kspace interactions do not contribute to this compute.</p>
|
|
</div>
|
|
<div class="section" id="related-commands">
|
|
<h2>Related commands</h2>
|
|
<p><em>compute group/group</em>_compute_group_group.html, <em>compute
|
|
heat/flux</em>_compute_heat_flux.html</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> |