  The all-electron exact muffin-tin orbitals method in combination with the
coherent-potential appproximation has been employed to investigate the ideal
tensile strengths of elemental V, Mo solids and V- and Mo-based random solid
solutions. The present ideal tensile strengths, calculated assuming isotropic
Poisson contraction, are 16.1, 26.7 and 37.6 GPa for bcc V in the [001], [111]
and [110] directions, respectively, and 26.7 GPa for bcc Mo in the [001]
direction, which are all in good agreement with the available theoretical data.
When a few percent Tc is introduced in Mo, it is found that the ideal strength
decreases in the [001] direction. For the V-based alloys, Cr increases and Ti
decreases the ideal tensile strength in all principal directions. Adding the
same concentration of Cr and Ti to V leads to ternary alloys with similar ideal
strength values as that of pure V. The alloying effects on the ideal strength
is explained using the electronic band structure.
