Zinc blende structure Zinc blende has the composition ZnS and its unit lattice is shown in Fig. 2.9. S2- anions are arranged in ccp and Zn2+ cations occupy half of the tetrahedral holes (Td holes). In this arrangement, each cation is coordinated by four anions, and each anion by four cations. Hence, this is a (4, 4)-structure. There are both four Zn2+ and S2- ions belonging to this unit lattice and the atomic ratio coincides with the formula of ZnS.