Structure prediction, high pressure effect and properties investigation of superhard B ₆ O

Ab initio data mining approach has been used in order to investigate B 6 O system and discover new possible modifications, besides experimentally known R -3 m ( α -B 6 O) structure and theoretically predicted Cmcm ( β -B 6 O) structure. DFT calculations were performed by two different functionals, LDA and PBE. In this work, we focus on the structure, mechanical, and electronic properties of the experimentally known α -B 6 O structure and newly predicted modifications with the B 6 O stoichiometry. Moreover, mechanical properties including elastic constants, bulk, shear and elastic moduli, Poisson’s ratio, Pugh’s criterion, and hardness are given for the investigated modifications of B 6 O. In particular, we have investigated the influence of the high pressure on the electronic and mechanical properties. Results of our study provide more insight in the B 6 O superhard material and open new possibilities for various device applications.