The real part of the atomic scattering factor of chlorine
<a href="//commons.wikimedia.org/wiki/User:Pieter_Kuiper" title="User:Pieter Kuiper">Pieter Kuiper</a>
<span class="int-own-work" lang="en">Own work</span>; data from <a rel="nofollow" class="external free" href="http://henke.lbl.gov/optical_constants/asf.html">http://henke.lbl.gov/optical_constants/asf.html</a>