Crystal structure of <a href="https://en.wikipedia.org/wiki/Brianite" class="extiw" title="en:Brianite">Brianite</a> (Na<sub>2</sub>CaMg(PO<sub>4</sub>)<sub>2</sub>) as "ball-and-stick-model" with view parallel to the b-axis.
<a href="https://de.wikipedia.org/wiki/Ra%27ike" class="extiw" title="de:Ra'ike">Ra'ike</a> (Wikipedia)
<span class="int-own-work" lang="en">Own work</span>