="o">+=</span> <span class="mi">1</span>

        <span class="k">if</span> <span class="n">return_descriptor</span><span class="p">:</span>
            <span class="n">d0</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">create_single</span><span class="p">(</span><span class="n">system</span><span class="p">,</span> <span class="n">centers</span><span class="p">)</span>
            <span class="n">np</span><span class="o">.</span><span class="n">copyto</sp