[en] Geometrical modeling of the B2 structure indicates that the tetrahedral interstitial site is always the largest both before and after an a/2 left-angle 111 right-angle translation on {110}, such as occurs during the slip of a partial dislocation in some B2 compounds. The tetrahedral site within the APB which trails a gliding a/2 left-angle 111 right-angle dislocation is larger than in the unslipped lattice, suggesting that interstitial atoms will segregate there. Also, some interstitial sites in a B2 lattice are larger than those in a bcc lattice of the same lattice parameter, suggesting that interstitials may have greater solubility in B2 compounds