lass="nb">bool</span> <span class="o">=</span> <span class="kc">False</span>
<span class="p">)</span> <span class="o">-&gt;</span> <span class="n">np</span><span class="o">.</span><span class="n">ndarray</span><span class="p">:</span>
    <span class="sa">r</span><span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Compute the LDA exchange-correlation potential from a density.</span>

<span class="sd">    | Args:</span>
<span class="sd">    |     s: iDEA.system.System, System object.</span>
<span