             &#39;numerical&#39;.</span>
<span class="sd">            attach (bool): Controls the behaviour of centers defined as</span>
<span class="sd">                atomic indices. If True, the centers tied to an atomic index will</span>
<span class="sd">                move together with the atoms with respect to which the derivatives</span>
<span class="sd">                are calculated against. If False, centers defined as atomic</span>
<span class="sd">                indices will be converted int