<p>Ball-and-stick model of the <a href="https://en.wikipedia.org/wiki/Bilirubin" class="extiw" title="en:Bilirubin">bilirubin</a> molecule as found in the crystal structure.
</p><p>Dashed lines are intramolecular hydrogen bonds.
</p><p><b>Colour code:</b>
</p>
<ul><li>Carbon, C: grey-black</li>
<li>Hydrogen, H: white</li>
<li>Nitrogen, N: blue</li>
<li>Oxygen, O: red</li></ul><p>Structure by X-ray crystallography from <a rel="nofollow" class="external text" href="https://dx.doi.org/10.1098/rspb.1978.0066"><i>Proc. R. Soc. Lond. B</i> (1978) <b>202</b>, 249-268</a>.
</p>
Image generated in <a rel="nofollow" class="external text" href="http://accelrys.com/products/discovery-studio/visualization/discovery-studio-visualizer.html">Accelrys DS Visualizer</a>.
Ben Mills
<span class="int-own-work" lang="en">Own work</span>