rge density of down electrons.</span>
<span class="sd">    |     up_p: np.ndarray, Charge density matrix of up electrons.</span>
<span class="sd">    |     down_p: np.ndarray, Charge density matrix of down electrons.</span>
<span class="sd">    |     K: np.ndarray, Single-particle kinetic energy operator [If None this will be computed from s]. (default = None)</span>
<span class="sd">    |     Vext: np.ndarray, Potential energy operator [If None this will be computed from s]. (default = None)</span>

<span 