n>
<span class="sd">            ValueError: If the atomic numbers in the given system are not</span>
<span class="sd">            included in the species given to this descriptor.</span>
<span class="sd">        &quot;&quot;&quot;</span>
        <span class="c1"># Check that the system does not have elements that are not in the list</span>
        <span class="c1"># of atomic numbers</span>
        <span class="n">zs</span> <span class="o">=</span> <span class="nb">set</span><span class="p">(</span><span cl