| An
interstitial atom is one that occupies a site in a crystal structure that
is normally unoccupied by the atoms of the structure. These sites are known
as interstitial sites and have volume associated with them into which a
hard sphere atom may be placed without causing distortion of the "rigid"
crystal structure.
Interstitial
sites in a crystal structure are associated with different numbers of lattice
atoms in their immediate neighborhood. Drawing lines through the centers
of these nearest neighbor atoms to the site generates coordination polyhedra
of the types shown. The gray sphere shown at the center of each coordination
figure represents the largest hard sphere interstitial that can fit in
the site. |
