      <span class="n">E_CH</span><span class="o">=</span><span class="n">n_ne</span><span class="o">*</span><span class="n">C_E</span><span class="o">**</span><span class="mi">3</span><span class="o">*</span><span class="n">CLogee</span><span class="o">/</span><span class="p">(</span><span class="mi">4</span><span class="o">*</span><span class="n">C_PI</span><span class="o">*</span><span class="n">C_E0</span><span class="o">**</span><span class="mi">2</span><span class="o">*</span><span class="n">C_ME</span