  It is generally assumed that one solute atom will occupy only one lattice
site in a substitutional solid solution. We here report an interesting
discovery by first-principles calculations that a large solute atom can replace
multiple matrix atoms in the elemental crystal of beryllium. Examination on
Groups IIIB, IVB, VB, VIB, and VA elements shows that Cr will substitute for
one, V and Mo for three, Sc, Y, Ti, Zr, Hf, W, Nb, Ta, As, Sb, and Bi for four,
and La for five Be atoms. Dissolution of Zr, Hf, Sc, and Y is exothermic,
suggesting a good solubility. At low concentration, the configurational entropy
resulted from one-for-multiple substitution is larger than in the one-for-one
substitution case. We find that Sc, Y, Zr, and Hf all have tendency to
aggregate in Be, but Sc is the weakest among them and thus can be expected to
improve the superplasticity of Be.
