ructor.</span>

<span class="sd">    For reference, see:</span>

<span class="sd">    &quot;Comparing molecules and solids across structural and alchemical</span>
<span class="sd">    space&quot;, Sandip De, Albert P. Bartók, Gábor Csányi and Michele Ceriotti,</span>
<span class="sd">    Phys.  Chem. Chem. Phys. 18, 13754 (2016),</span>
<span class="sd">    https://doi.org/10.1039/c6cp00415f</span>
<span class="sd">    &quot;&quot;&quot;</span>

    <span class="k">def</span> <span class="fm">__init__</s