Half-metallicity in the half-Heusler RbSrC, RbSrSi and RbSrGe compounds

► There has been little work on HM ferromagnets with Heusler structure excluding transition metals. ► The optimization revealed the lowest energy for the structure type (I) for RbSrX(X=C, Si, Ge) compounds. ► The half metallicity is found to be robust with respect to the lattice constant contraction.