Structure searches and superconductor discovery in XB2 (X = Sc, Ti, V, Cr, and Tc)

With extensive structure searches for XB 2 (X = Sc, Ti, V, Cr, and Tc) under pressures up to 100 GPa, we uncovered that the crystal structures of these compounds with the lowest enthalpy have the same space group ( P 6/ mmm ) as MgB 2 at ambient pressure.