_node_match</span><span class="p">(</span><span class="s2">&quot;specie&quot;</span><span class="p">,</span> <span class="s2">&quot;C&quot;</span><span class="p">)</span>

        <span class="k">for</span> <span class="n">group</span> <span class="ow">in</span> <span class="n">groups</span><span class="p">:</span>
            <span class="n">atoms</span> <span class="o">=</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">molecule</span><span class="p">[</spa