mirror of
https://github.com/QuantumPackage/qp2.git
synced 2024-12-30 23:25:39 +01:00
270 lines
11 KiB
HTML
270 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>Excited states — 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="Natural orbitals" href="natural_orbitals.html" />
|
|||
|
|
<link rel="prev" title="Interfaces" href="interfaces.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 current"><a class="current reference internal" href="#">Excited states</a></li>
|
|||
|
|
<li class="toctree-l1"><a class="reference internal" href="natural_orbitals.html">Natural orbitals</a></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> »</li>
|
|||
|
|
|
|||
|
|
<li>Excited states</li>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<li class="wy-breadcrumbs-aside">
|
|||
|
|
|
|||
|
|
|
|||
|
|
<a href="../_sources/users_guide/excited_states.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="excited-states">
|
|||
|
|
<span id="id1"></span><h1>Excited states<a class="headerlink" href="#excited-states" title="Permalink to this headline">¶</a></h1>
|
|||
|
|
<p>It is possible to run excited states calculations with the quantum
|
|||
|
|
package. To do this, set <a class="reference internal" href="../modules/determinants.html#cmdoption-determinants-arg-n-states"><code class="xref std std-option docutils literal notranslate"><span class="pre">determinants</span> <span class="pre">n_states</span></code></a> to the number
|
|||
|
|
of requested states. The selection criterion will be the maximum of the
|
|||
|
|
selection criteria for each state. If the Davidson diagonalization has
|
|||
|
|
difficulties to converge, increase the <a class="reference internal" href="../modules/davidson.html#cmdoption-davidson-arg-n-states-diag"><code class="xref std std-option docutils literal notranslate"><span class="pre">davidson</span> <span class="pre">n_states_diag</span></code></a>
|
|||
|
|
value.</p>
|
|||
|
|
<p>When computing multiple states, it is good to have the
|
|||
|
|
<a class="reference internal" href="../modules/determinants.html#cmdoption-determinants-arg-s2-eig"><code class="xref std std-option docutils literal notranslate"><span class="pre">determinants</span> <span class="pre">s2_eig</span></code></a> flag <code class="docutils literal notranslate"><span class="pre">true</span></code>. This will force the Davidson
|
|||
|
|
algorithm to choose only vectors with a value of <span class="math notranslate nohighlight">\(\widehat{S^2}\)</span> equal to
|
|||
|
|
<a class="reference internal" href="../modules/determinants.html#cmdoption-determinants-arg-expected-s2"><code class="xref std std-option docutils literal notranslate"><span class="pre">determinants</span> <span class="pre">expected_s2</span></code></a>. Otherwise, different spin states
|
|||
|
|
will come out in the diagonalization.</p>
|
|||
|
|
<p>The <em>Quantum Package</em> doesn’t take account of the symmetry. Due to numerical noise,
|
|||
|
|
excited states of different symmetries may enter in the calculation.
|
|||
|
|
Note that it is possible to make state-average calculation of states
|
|||
|
|
with different symmetries and/or different spin multiplicities.</p>
|
|||
|
|
<p>To include excited state of all possible symmetries, a simple trick is
|
|||
|
|
to run a preliminary multi-state <abbr title="Configuration Interaction with Single Excitations">CIS</abbr> calculation using the <a class="reference internal" href="../programs/cis.html#cis"><span class="std std-ref">cis</span></a>
|
|||
|
|
program, and then running the selected <abbr title="Full Configuration Interaction">FCI</abbr> restarting from the <abbr title="Configuration Interaction with Single Excitations">CIS</abbr>
|
|||
|
|
states, setting <a class="reference internal" href="../modules/determinants.html#cmdoption-determinants-arg-read-wf"><code class="xref std std-option docutils literal notranslate"><span class="pre">determinants</span> <span class="pre">read_wf</span></code></a> to <code class="docutils literal notranslate"><span class="pre">true</span></code>.</p>
|
|||
|
|
<p>Usually, it is good practice to use state-averaged natural <abbr title="Molecular Orbitals">MOs</abbr> so that
|
|||
|
|
all states have <abbr title="Molecular Orbitals">MOs</abbr> of comparable quality. This allows for a faster
|
|||
|
|
convergence of excitation energies.</p>
|
|||
|
|
<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">scf()</span></code>, <code class="xref c c-func docutils literal notranslate"><span class="pre">cis()</span></code> and
|
|||
|
|
<code class="xref c c-func docutils literal notranslate"><span class="pre">fci()</span></code> programs.</p>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
|
|||
|
|
|
|||
|
|
</div>
|
|||
|
|
|
|||
|
|
</div>
|
|||
|
|
<footer>
|
|||
|
|
|
|||
|
|
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
|
|||
|
|
|
|||
|
|
<a href="natural_orbitals.html" class="btn btn-neutral float-right" title="Natural orbitals" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<a href="interfaces.html" class="btn btn-neutral" title="Interfaces" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
|
|||
|
|
|
|||
|
|
</div>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<hr/>
|
|||
|
|
|
|||
|
|
<div role="contentinfo">
|
|||
|
|
<p>
|
|||
|
|
© 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>
|