Electronic structures of new layered hexaboron Cr-B compounds from first principles

摘要

Based on crystal chemistry rationale whereby tetrahedral B4 in CrB4 and honeycomb-like array B2 in CrB2 stabilize thanks to electron transfer from Cr to B and using density functional theory DFT based calculations, trends of cohesive energies, charge transfers and geometry optimized structures were obtained. From the results, new honeycomb boron extended network structures embedding one and two Cr atoms were proposed within the Cr-B phase diagram. Specifically, newfound CrB6 and Cr2B6 were calculated to be stable thanks to electron transfer from Cr onto the boron honeycomb-like network needed for its stabilization. Such new layered borides with extended networks are likely to open new developments in chemistry and materials science.