A first principles study of the elastic properties in perovskite-type RRh3B and RRh3C with R = Sc, Y and La

First principles calculations have been performed on perovskite-type RRh3B and RRh3C (R = Sc, Y and La) compounds to obtain the equilibrium lattice constants and elastic properties such as the elastic constants, bulk moduli, shear moduli, and Young’s moduli. The calculated lattice constants are in excellent agreement with the experimental results. A new relationship between the bulk modulus and the nearest neighbor distance is proposed for the present systems.