Structural, mechanical, optical, thermodynamical and phonon properties of stable ReB2 polymorphs from density functional calculations

Abstract

Three mechanically and dynamically stable polymorphs of rhenium diboride (ReB2) (space group: P63/mmc, No: 194), (space group: R-3m, No: 166) and (space group: Pmmn, No: 59) were thoroughly analysed within the framework of Density Functional Theory from the structural, mechanical, optical, thermodynamical and phonon properties point of view. The calculated hardness of rhombohedral structure suggests that it can be even harder than well known hexagonal ReB2.