| Answer | Crossword Clue |
|---|---|
| interstitial | an extra atom in a crystal lattice, causing a defect |
| interstitials | INTERSTITIAL, an extra atom in a crystal lattice, causing a defect |
| vacancy | A defect in a crystal lattice, consisting of the absence of an atom or an ion from a position where there should be one |
| vacancies | A defect in a crystal lattice, consisting of the absence of an atom or an ion from a position where there should be one |
