DFT prediction of a novel molybdenum tetraboride superhard material

Abstract

In this work, we predict that MoB₄ with monoclinic structure (<italic>C</italic>2/<italic>m</italic>) and orthorhombic structure (<italic>Immm</italic>) are potential superhard materials because of the 3D-network B–B covalent bonds. In addition, the hardness of MoB₄ is attributed to the <italic>B</italic>/<italic>G</italic> ratio and <italic>c</italic>/<italic>a</italic> ratio.