A van der Waals' surface coloured according to charge, superimposed on a ball-and-stick model of the cyanic acid molecule, HOCN. Red represents partially negatively charged regions, blue represents partially positively charged regions, and white represents neutral (uncharged) regions.
<a href="//commons.wikimedia.org/wiki/User:Michael_Gongshun" title="User:Michael Gongshun">Michael Gongshun</a>
<span class="int-own-work" lang="en">Own work</span>