Elastic moduli ofB12and its compounds

We have calculated the bulk modulus and all the elastic moduli that can be obtained from uniaxial strains of ${\mathrm{B}}_{12}$, ${\mathrm{B}}_{12}$${\mathrm{C}}_{3}$, ${\mathrm{B}}_{13}$${\mathrm{C}}_{2}$, ${\mathrm{B}}_{12}$${\mathrm{O}}_{2}$, and ${\mathrm{B}}_{12}$${\mathrm{As}}_{2}$. All atoms are allowed to relax to their equilibrium positions under strain and the errors incurred by failure to do so are revealed.