diff --git a/.buildinfo b/.buildinfo
index 26129909d..5346b4ea9 100644
--- a/.buildinfo
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diff --git a/.doctrees/Tutorials/CCP5-June-2021.doctree b/.doctrees/Tutorials/CCP5-June-2021.doctree
index 3367e0fbf..3a27ec8cf 100644
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diff --git a/.doctrees/environment.pickle b/.doctrees/environment.pickle
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index f278a332a..a718a1125 100644
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-  <title>Motivation &mdash; quippy 7c428af documentation</title>
+  <title>Motivation &mdash; quippy 0e1d713 documentation</title>
       <link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
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@@ -44,7 +44,7 @@
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           </a>
               <div class="version">
-                7c428af
+                0e1d713
               </div>
 <div role="search">
   <form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
@@ -133,13 +133,13 @@
           <div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
            <div itemprop="articleBody">
              
-  <center><p><img alt="22859e7c5e72468aa3ad04bea3739c97" src="../_images/warwick-logo.png" /></p>
+  <center><p><img alt="d1a9b4c28bf34f5cb99671a26fc22843" src="../_images/warwick-logo.png" /></p>
 <h1><p>Quantum Mechanics and Interatomic Potentials – the QUIP code</p>
 </h1><h3><p>James Kermode</p>
 </h3><p>Warwick Centre for Predictive Modelling / School of Engineering University of Warwick</p>
 <h4><p>CCP5++ Software Seminar - 17th June 2021</p>
-</h4><table bgcolor="#ffffff"><tr><td><p><img alt="e8d3fe5147614ab48fa4035f08809246" class="no-scaled-link" src="../_images/WCPM_logo_text.png" style="width: 100%;" /></p>
-</td><td><p><img alt="a6da067e6bc24491a6a8d48f3676b130" class="no-scaled-link" src="../_images/hybrid.png" style="width: 100%;" /></p>
+</h4><table bgcolor="#ffffff"><tr><td><p><img alt="0a032d4bb0714324bd8b25b2af58db3c" class="no-scaled-link" src="../_images/WCPM_logo_text.png" style="width: 100%;" /></p>
+</td><td><p><img alt="6b7b288893974b86931c366496b6958a" class="no-scaled-link" src="../_images/hybrid.png" style="width: 100%;" /></p>
 </td></tr></table></center><p><em>These slides will subsequently be made available at https://libatoms.github.io/QUIP/Tutorials</em></p>
 <div class="nbinput nblast docutils container">
 <div class="prompt highlight-none notranslate"><div class="highlight"><pre><span></span>[ ]:
@@ -190,7 +190,7 @@ <h1>Motivation<a class="headerlink" href="#Motivation" title="Permalink to this
 </ul>
 </li>
 </ul>
-<center><p><img alt="3c8216ccb976451aa37c9c2562e59552" class="no-scaled-link" src="../_images/multiscale.png" style="width: 80%;" /></p>
+<center><p><img alt="3c4ff2453d1946bb8a4dab56b07f1eb2" class="no-scaled-link" src="../_images/multiscale.png" style="width: 80%;" /></p>
 </center><p><em>Image credit: Gábor Csányi</em></p>
 </section>
 <section id="The-QUIP-code">
@@ -408,7 +408,7 @@ <h1>Using QUIP with Python and the Atomic Simulation Environment<a class="header
 <li><p><a class="reference external" href="https://jupyter.org/">jupyter</a>/IPython notebooks encourage reproducible research</p></li>
 <li><p><a class="reference external" href="https://jupyter.org/">anaconda</a> distribution and package management system</p></li>
 </ul>
-<center><p><img alt="d6e10b0dc9c14002b9042b8c90788bb3" class="no-scaled-link" src="../_images/scipy-stack.png" style="width: 70%;" /></p>
+<center><p><img alt="2bf219a3f8f94b8982ac2b38f6600492" class="no-scaled-link" src="../_images/scipy-stack.png" style="width: 70%;" /></p>
 </center><p><a class="reference external" href="http://www.scipy.org">http://www.scipy.org</a></p>
 </section>
 <section id="Atomic-Simulation-Environment-(ASE)">
@@ -418,7 +418,7 @@ <h1>Atomic Simulation Environment (ASE)<a class="headerlink" href="#Atomic-Simul
 <li><p>Wide range of calculators, very similar data model for Atoms objects to QUIP</p></li>
 <li><p>Can use many codes as drop-in replacements:</p></li>
 </ul>
-<center><p><img alt="47aea1ffa5e742819ffe5383ff1c89c9" class="no-scaled-link" src="../_images/ase-calculators.png" style="width: 60%;" /></p>
+<center><p><img alt="c601a72fb7664711867d9b0f4021214a" class="no-scaled-link" src="../_images/ase-calculators.png" style="width: 60%;" /></p>
 </center><p><a class="reference external" href="https://wiki.fysik.dtu.dk/ase/">https://wiki.fysik.dtu.dk/ase/</a></p>
 </section>
 <section id="quippy-demo:-analysing-GAP-models-with-predictive-variance">
diff --git a/Tutorials/adaptive-qmmm-references.html b/Tutorials/adaptive-qmmm-references.html
index eb3244363..0da9f8a8f 100644
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+++ b/Tutorials/adaptive-qmmm-references.html
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-  <title>References &mdash; quippy 7c428af documentation</title>
+  <title>References &mdash; quippy 0e1d713 documentation</title>
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diff --git a/Tutorials/adaptive-qmmm-solutions.html b/Tutorials/adaptive-qmmm-solutions.html
index 167033e5e..896ae86a1 100644
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-  <title>Solutions &mdash; quippy 7c428af documentation</title>
+  <title>Solutions &mdash; quippy 0e1d713 documentation</title>
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diff --git a/Tutorials/adaptive-qmmm-step0.html b/Tutorials/adaptive-qmmm-step0.html
index b9a38dc78..1857cfb09 100644
--- a/Tutorials/adaptive-qmmm-step0.html
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-  <title>Introduction &mdash; quippy 7c428af documentation</title>
+  <title>Introduction &mdash; quippy 0e1d713 documentation</title>
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diff --git a/Tutorials/adaptive-qmmm-step1.html b/Tutorials/adaptive-qmmm-step1.html
index f295778e8..2b7424ffe 100644
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-  <title>Step 1: Setup of the Silicon model system &mdash; quippy 7c428af documentation</title>
+  <title>Step 1: Setup of the Silicon model system &mdash; quippy 0e1d713 documentation</title>
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diff --git a/Tutorials/adaptive-qmmm-step2.html b/Tutorials/adaptive-qmmm-step2.html
index 20ee69a5d..7fc11ac03 100644
--- a/Tutorials/adaptive-qmmm-step2.html
+++ b/Tutorials/adaptive-qmmm-step2.html
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   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-  <title>Step 2: Classical MD simulation of fracture in Si &mdash; quippy 7c428af documentation</title>
+  <title>Step 2: Classical MD simulation of fracture in Si &mdash; quippy 0e1d713 documentation</title>
       <link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
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@@ -521,7 +521,7 @@ <h3>Milestone 2.2<a class="headerlink" href="#milestone-2-2" title="Permalink to
 obeys the expected <span class="math notranslate nohighlight">\(1/\sqrt{r}\)</span> divergence near the crack tip, and tends
 to a constant value ahead of the crack, due to the thin strip loading. <em>Hint:</em>
 use a mask to select the relevant atoms, as we did when fixing the edge atoms
-above. You can use the matplotlib <a class="reference external" href="https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.plot.html#matplotlib.pyplot.plot" title="(in Matplotlib v3.9.0)"><code class="xref py py-func docutils literal notranslate"><span class="pre">plot()</span></code></a> function to
+above. You can use the matplotlib <a class="reference external" href="https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.plot.html#matplotlib.pyplot.plot" title="(in Matplotlib v3.9.1)"><code class="xref py py-func docutils literal notranslate"><span class="pre">plot()</span></code></a> function to
 produce a plot.</p>
 </section>
 <section id="time-averaged-stress-field">
@@ -647,7 +647,7 @@ <h3>Milestone 2.2<a class="headerlink" href="#milestone-2-2" title="Permalink to
 <p>The following plot shows the evolution of <cite>G</cite> (blue) and of the
 position of the crack (red; stored as <cite>crack_pos_x</cite>). Note that a
 second vertical axis can be produced with the
-<a class="reference external" href="https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.twinx.html#matplotlib.pyplot.twinx" title="(in Matplotlib v3.9.0)"><code class="xref py py-func docutils literal notranslate"><span class="pre">twinx()</span></code></a> function.</p>
+<a class="reference external" href="https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.twinx.html#matplotlib.pyplot.twinx" title="(in Matplotlib v3.9.1)"><code class="xref py py-func docutils literal notranslate"><span class="pre">twinx()</span></code></a> function.</p>
 <a class="reference internal image-reference" href="../_images/energy-release-rate-crack-position.png"><img alt="../_images/energy-release-rate-crack-position.png" class="align-center" src="../_images/energy-release-rate-crack-position.png" style="width: 600px;" /></a>
 <p>In this case the crack actually arrests for a while at around <span class="math notranslate nohighlight">\(t
 = 6\)</span> ps. This is another characteristic feature of non-brittle
diff --git a/Tutorials/adaptive-qmmm-step3.html b/Tutorials/adaptive-qmmm-step3.html
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-  <title>Step 3: LOTF hybrid MD simulation of fracture in Si &mdash; quippy 7c428af documentation</title>
+  <title>Step 3: LOTF hybrid MD simulation of fracture in Si &mdash; quippy 0e1d713 documentation</title>
       <link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
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diff --git a/Tutorials/adaptive-qmmm-theory.html b/Tutorials/adaptive-qmmm-theory.html
index 8e1653943..b7a8a72ac 100644
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-  <title>Theoretical background &mdash; quippy 7c428af documentation</title>
+  <title>Theoretical background &mdash; quippy 0e1d713 documentation</title>
       <link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
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+                0e1d713
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diff --git a/Tutorials/adaptive-qmmm.html b/Tutorials/adaptive-qmmm.html
index ff243a2a3..663040522 100644
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   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-  <title>Adaptive QM/MM MD of Fracture in Silicon &mdash; quippy 7c428af documentation</title>
+  <title>Adaptive QM/MM MD of Fracture in Silicon &mdash; quippy 0e1d713 documentation</title>
       <link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
       <link rel="stylesheet" type="text/css" href="../_static/css/theme.css" />
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-                7c428af
+                0e1d713
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diff --git a/Tutorials/adglass.html b/Tutorials/adglass.html
index 0c04e02a4..e2831c41d 100644
--- a/Tutorials/adglass.html
+++ b/Tutorials/adglass.html
@@ -4,7 +4,7 @@
   <meta charset="utf-8" /><meta name="generator" content="Docutils 0.19: https://docutils.sourceforge.io/" />
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-  <title>Molecular Dynamics Simulation of Fracture in Quartz &mdash; quippy 7c428af documentation</title>
+  <title>Molecular Dynamics Simulation of Fracture in Quartz &mdash; quippy 0e1d713 documentation</title>
       <link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
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@@ -174,14 +174,14 @@ <h2>Starting a fracture simulation<a class="headerlink" href="#starting-a-fractu
 refers to the directory where the the QUIP source code is located.</p>
 </div>
 <p>To make the command <cite>crack</cite> availale, copy the executable
-<code class="docutils literal notranslate"><span class="pre">${QUIP_ROOT}/build/${QUIP_ARCH}</span></code> to a directory on your <span class="target" id="index-2"></span><a class="reference external" href="https://matplotlib.org/stable/install/environment_variables_faq.html#envvar-PATH" title="(in Matplotlib v3.9.0)"><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PATH</span></code></a>,
+<code class="docutils literal notranslate"><span class="pre">${QUIP_ROOT}/build/${QUIP_ARCH}</span></code> to a directory on your <span class="target" id="index-2"></span><a class="reference external" href="https://matplotlib.org/stable/install/environment_variables_faq.html#envvar-PATH" title="(in Matplotlib v3.9.1)"><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PATH</span></code></a>,
 e.g. <code class="docutils literal notranslate"><span class="pre">~/bin</span></code>.</p>
 <p>Similarly, to compile <cite>eval</cite> run:</p>
 <div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$ make QUIP_Programs/eval
 </pre></div>
 </div>
 <p>It is highly recommended to change the name when copying the <cite>eval</cite> prgram to a
-directory on <span class="target" id="index-3"></span><a class="reference external" href="https://matplotlib.org/stable/install/environment_variables_faq.html#envvar-PATH" title="(in Matplotlib v3.9.0)"><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PATH</span></code></a> to avoid a clash with the builtin <code class="docutils literal notranslate"><span class="pre">eval</span></code> command.</p>
+directory on <span class="target" id="index-3"></span><a class="reference external" href="https://matplotlib.org/stable/install/environment_variables_faq.html#envvar-PATH" title="(in Matplotlib v3.9.1)"><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PATH</span></code></a> to avoid a clash with the builtin <code class="docutils literal notranslate"><span class="pre">eval</span></code> command.</p>
 <p>Start the simulation by running the <cite>crack</cite> program, which takes
 the “stem” of the input filenames as its only argument:</p>
 <div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$ crack quartz_crack &gt; quartz_crack.out &amp;
diff --git a/Tutorials/committee_modelling.html b/Tutorials/committee_modelling.html
index 3ca3b443c..62b496f69 100644
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-  <title>Committee Modelling using GAP potentials &mdash; quippy 7c428af documentation</title>
+  <title>Committee Modelling using GAP potentials &mdash; quippy 0e1d713 documentation</title>
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-  <title>Tutorials &mdash; quippy 7c428af documentation</title>
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