  We present an extensive first-principles database of solute-vacancy,
homoatomic, heteroatomic solute-solute, and solute-solute-vacancy binding
energies of relevant alloying elements in aluminum. We particularly focus on
the systems with major alloying elements in aluminum, i.e., Cu, Mg, and Si. We
consider physical factors such as solute size and formation energies of
intermetallic compounds to correlate with binding energies. Systematic studies
of the homoatomic solute-solute-vacancy and heteroatomic (Cu, Mg, or
Si)-solute-vacancy complexes reveal the overarching effect of the vacancy in
stabilizing solute-solute pairs. The computed binding energies of the
solute-solute-vacancy triplet successfully explain several experimental
observations that remained unexplained by the reported pair binding energies in
literature. The binding energy database presented here elucidates the
interaction between solute cluster and vacancy in aluminum, and it is expected
to provide insight into the design of advanced Al alloys with tailored
properties.
