Rutile structure
= Rutile structure
A tetragonal $AB_2$ <crystal structure> with sixfold cation and threefold anion <coordination numbers>. A common fractional-coordinate description has A at $(0,0,0)$ and $(1/2,1/2,1/2)$, and B at $\pm(u,u,0)$ and $\pm(1/2+u,1/2-u,1/2)$, interpreted modulo integer lattice translations. The cation coordination is a distorted octahedron and the anion coordination is a planar triangle. <Titanium dioxide> in its rutile polymorph is an example.