Structure, bonding, and hardness of CrB${}_4$: a superhard material?

Haiyang Niu, Jiaqi Wang, Xing-Qiu Chen +5

By electron and X-ray diffraction we establish that the CrB${}_4$ compound discovered over 40 years ago crystallizes in the $oP10$ (\emph{Pnnm}) structure, in disagreement with previ…