9
1
mirror of https://github.com/QuantumPackage/qp2.git synced 2024-12-30 23:25:39 +01:00
qp2/doc/users_guide/natural_orbitals.html

299 lines
11 KiB
HTML
Raw Normal View History

2019-01-25 14:17:34 +01:00
<!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>Natural orbitals &mdash; Quantum Package 2.0 documentation</title>
<link rel="stylesheet" href="../_static/css/theme.css" type="text/css" />
<link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
<link rel="index" title="Index" href="../genindex.html" />
<link rel="search" title="Search" href="../search.html" />
<link rel="next" title="Printing the near-FCI wave function" href="printing.html" />
<link rel="prev" title="Excited states" href="excited_states.html" />
<script src="../_static/js/modernizr.min.js"></script>
</head>
<body class="wy-body-for-nav">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search">
<a href="../index.html" class="icon icon-home"> Quantum Package
</a>
<div class="version">
2.0
</div>
<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">Introduction</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../intro/install.html">Installation</a></li>
<li class="toctree-l1"><a class="reference internal" href="../intro/selected_ci.html">Selected Configuration Interaction</a></li>
</ul>
<p class="caption"><span class="caption-text">User's guide</span></p>
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="quickstart.html">Quick-start guide</a></li>
<li class="toctree-l1"><a class="reference internal" href="interfaces.html">Interfaces</a></li>
<li class="toctree-l1"><a class="reference internal" href="excited_states.html">Excited states</a></li>
<li class="toctree-l1 current"><a class="current reference internal" href="#">Natural orbitals</a><ul>
<li class="toctree-l2"><a class="reference internal" href="#summary">Summary</a></li>
<li class="toctree-l2"><a class="reference internal" href="#extracting-natural-orbitals">Extracting natural orbitals</a></li>
<li class="toctree-l2"><a class="reference internal" href="#hands-on">Hands on</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="printing.html">Printing the near-<abbr title="Full Configuration Interaction">FCI</abbr> wave function</a></li>
<li class="toctree-l1"><a class="reference internal" href="plugins.html">Working with external plugins</a></li>
<li class="toctree-l1"><a class="reference internal" href="qp_plugins.html">qp_plugins</a></li>
<li class="toctree-l1"><a class="reference internal" href="index.html">Index of commands</a></li>
<li class="toctree-l1"><a class="reference internal" href="index.html#index-of-programs">Index of programs</a></li>
</ul>
<p class="caption"><span class="caption-text">Programmer's guide</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../programmers_guide/programming.html">Programming in the <em>Quantum Package</em></a></li>
<li class="toctree-l1"><a class="reference internal" href="../programmers_guide/ezfio.html">EZFIO</a></li>
<li class="toctree-l1"><a class="reference internal" href="../programmers_guide/plugins.html">Developing plugins</a></li>
<li class="toctree-l1"><a class="reference internal" href="../programmers_guide/index.html">Index for programmers</a></li>
<li class="toctree-l1"><a class="reference internal" href="../programmers_guide/plugins.html">Developing plugins</a></li>
</ul>
<p class="caption"><span class="caption-text">Appendix</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../appendix/benchmarks.html">Benchmarks</a></li>
<li class="toctree-l1"><a class="reference internal" href="../appendix/research.html">Some research made with the <em>Quantum Package</em></a></li>
<li class="toctree-l1"><a class="reference internal" href="../appendix/license.html">License</a></li>
<li class="toctree-l1"><a class="reference internal" href="../appendix/contributors.html">Contributors</a></li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="../index.html">Quantum Package</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="../index.html">Docs</a> &raquo;</li>
<li>Natural orbitals</li>
<li class="wy-breadcrumbs-aside">
<a href="../_sources/users_guide/natural_orbitals.rst.txt" rel="nofollow"> View page source</a>
</li>
</ul>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<div class="section" id="natural-orbitals">
<h1>Natural orbitals<a class="headerlink" href="#natural-orbitals" title="Permalink to this headline"></a></h1>
<div class="section" id="summary">
<h2>Summary<a class="headerlink" href="#summary" title="Permalink to this headline"></a></h2>
<p>To produce state-average natural orbitals, run</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">qp_run</span> <span class="n">save_natorb</span> <span class="n">file</span><span class="o">.</span><span class="n">ezfio</span>
</pre></div>
</div>
<p>The MOs will be replaced, so the two-electron integrals and the wave
function are invalidated as well.</p>
</div>
<div class="section" id="extracting-natural-orbitals">
<h2>Extracting natural orbitals<a class="headerlink" href="#extracting-natural-orbitals" title="Permalink to this headline"></a></h2>
<p>Once obtained the near <abbr title="Full Configuration Interaction">FCI</abbr> wave function, one can obtain many
Onquantities related to it. e of these quantities are the natural
Onorbitals which have the properties of diagonalizing the one-body
Ondensity matrix:</p>
<blockquote>
<div><div class="math notranslate nohighlight">
\[\rho_{ij} = \delta_{ij}\]</div>
</div></blockquote>
<p>where the element of the one-body density matrix <span class="math notranslate nohighlight">\(\rho_{ij}\)</span> is
define as:</p>
<blockquote>
<div><div class="math notranslate nohighlight">
\[\rho_{ij} = \langle \Psi | \left( a^{\dagger}_{j,\alpha} a_{i,\alpha} + a^{\dagger}_{j,\beta} a_{i,\beta} \right) |&nbsp;\Psi&nbsp;\rangle\]</div>
</div></blockquote>
<p>These orbitals are in general known to be better than the usual <abbr title="Hartree-Fock">HF</abbr>
<abbr title="Molecular Orbitals">MOs</abbr> as they are obtained from a correlated wave function. To use these
orbitals for future calculations, one has to replace the current <abbr title="Molecular Orbitals">MOs</abbr>
by the natural orbitals. To do so, just run:</p>
<div class="code highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">qp_run</span> <span class="n">save_natorb</span> <span class="n">file</span><span class="o">.</span><span class="n">ezfio</span>
</pre></div>
</div>
</div>
<div class="section" id="hands-on">
<h2>Hands on<a class="headerlink" href="#hands-on" title="Permalink to this headline"></a></h2>
<div class="admonition important">
<p class="first admonition-title">Important</p>
<p class="last">As the <abbr title="Molecular Orbitals">MOs</abbr> are changed, for the sake of coherence of future
calculations, the save_natorb program <em>automatically removes the
current wave function</em> stored in the <a class="reference external" href="http://gitlab.com/scemama/EZFIO">EZFIO</a> database and replaces
it by a single Slater determinant corresponding to a <abbr title="Hartree-Fock">HF</abbr> occupation
of the new spin orbitals. Also, all the keywords to read the one-
and two-electron integrals on the <abbr title="Molecular Orbital">MO</abbr> basis are set to <code class="docutils literal notranslate"><span class="pre">None</span></code> in
order to be sure to avoid reading integrals incompatible with the
current set of <abbr title="Molecular Orbitals">MOs</abbr>.</p>
</div>
<div class="admonition seealso">
<p class="first admonition-title">See also</p>
<p class="last">The documentation of the <code class="xref c c-func docutils literal notranslate"><span class="pre">save_natorb()</span></code> program.</p>
</div>
</div>
</div>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="printing.html" class="btn btn-neutral float-right" title="Printing the near-FCI wave function" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="excited_states.html" class="btn btn-neutral" title="Excited states" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<p>
&copy; Copyright 2018, A. Scemama, E. Giner
</p>
</div>
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/rtfd/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" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></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 async="async" type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
<script type="text/javascript" src="../_static/js/theme.js"></script>
<script type="text/javascript">
jQuery(function () {
SphinxRtdTheme.Navigation.enable(true);
});
</script>
</body>
</html>