peckle particles, here, we logged the start index and end index of speckle particle, and computed the number of speckle particles.</p>
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<div class="prompt highlight-none notranslate"><div class="highlight"><pre><span></span>[4]:
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<div class="input_area highlight-ipython3 notranslate"><div class="highlight"><pre><span></span><span class="c1"># Add the default force field</span>
<span class="n">model</span><span class="o">.</span><span class="n