rivative array and the second is the descriptor array.</span>
<span class="sd">            Otherwise only returns the derivatives array. The derivatives array</span>
<span class="sd">            is a either a 4D or 5D array, depending on whether you have</span>
<span class="sd">            provided a single or multiple systems. If the output shape for each</span>
<span class="sd">            system is the same, a single monolithic numpy array is returned.</span>
<span class="sd">            For variable siz