CHM 501

36. Show that the zinc blende structure shown in Figure 5.6 matches the stoichiometry.

Answer

Using the cell on the left provides the answer readily. There are 4 Zn (black circles) completely enclosed in the cell shown by the dashed lines. The sulfides (gray circles) occupy each corner of the cell with 1/8 of the S2– located within the cell and each face of the cell with 1/2 of the S2– within the cell. Thus, the number of sulfides in the cell is 8(1/8) + 6(1/2) = 4. The stoichiometry within the unit cell is Zn4S4 = ZnS.