MO Diagram — O₂

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  <text class="lab" x="40" y="20">O (2p)</text>
  <text class="lab" x="380" y="20">O (2p)</text>
  <text class="lab" x="200" y="20">MO</text>

  <!-- 2p AOs -->
  <line class="lev" x1="40" y1="120" x2="100" y2="120"/>
  <line class="lev" x1="380" y1="120" x2="440" y2="120"/>
  <text x="68" y="115" class="e">↑↓ ↑ ↑</text>
  <text x="408" y="115" class="e">↑↓ ↑ ↑</text>

  <!-- σ2p -->
  <line class="lev" x1="200" y1="280" x2="260" y2="280"/>
  <text x="170" y="295">σ2p</text><text x="220" y="275" class="e">↑↓</text>

  <!-- π2p (degenerate) -->
  <line class="lev" x1="200" y1="220" x2="240" y2="220"/>
  <line class="lev" x1="250" y1="220" x2="290" y2="220"/>
  <text x="160" y="225">π2p</text><text x="212" y="215" class="e">↑↓</text><text x="263" y="215" class="e">↑↓</text>

  <!-- π*2p (unpaired) -->
  <line class="lev" x1="200" y1="160" x2="240" y2="160"/>
  <line class="lev" x1="250" y1="160" x2="290" y2="160"/>
  <text x="155" y="165">π*2p</text><text x="220" y="155" class="e">↑</text><text x="270" y="155" class="e">↑</text>

  <!-- σ*2p -->
  <line class="lev" x1="200" y1="80" x2="260" y2="80"/>
  <text x="165" y="85">σ*2p</text>

  <!-- ties -->
  <line class="tie" x1="100" y1="120" x2="200" y2="160"/>
  <line class="tie" x1="380" y1="120" x2="290" y2="160"/>

  <text class="lab" x="200" y="330">Bond order = (8 - 4)/2 = 2 · paramagnetic (2 unpaired e⁻)</text>
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