Multiply charged ions are emitted following bombardment of Al(100) and Si(111) by low energy Si + and P + ions. The ion formation is attributed to inner-shell electron promotion during a hard collision between symmetric or nearly symmetric atomic species, followed by Auger decay outside the surface. The relative yield of triply charged Si ions for Si + →Si(111) is much smaller than that of triply charged Al ions in direct recoil Si + →Al(100) experiments. This difference can be explained by assuming that only one 2p hole is produced in a Si atom during the symmetric collision, whereas a double 2p hole is also produced in the Al atom following the nearly symmetric Si–Al collision. Further evidence is provided by the complimentary experiment P + →Si(111), where Si 3+ regains its intensity and Si 4+ emerges as a result of a double 2p hole decay with shake-off.