[alumina]

Hi,
I have a problem with this exercise: "describe the structure of CuI given as reference data the r(Cu +) = er 96pm (I-) = 216 pm".
Now, the structure of CuI is Blende type: iodide form the lattice and the Cu cation is in the tetrahedral cavity ,but  the ratio of the cation's radius and anion is equal to 0.444, which denotes octahedral cavities.
Why ?

[AWK]

Check your input data

http://en.wikipedia.org/wiki/Copper(I)_iodide