4. For each of the following crystal structures, represent the indicated plane in the manner of Figures 3.11 and 3.12, showing both anions and cations: (a) (100) plane for the rock salt crystal structure (b) (110) plane for the cesium chloride crystal structure (c) (111) plane for the zinc blende crystal structure (d) (110) plane for the perovskite crystal structure. D (a) (b) Figure 3.11 (a) Reduced-sphere FCC unit cell with the (110) plane. (b) Atomic packing of an FCC (110) plane. Corresponding atom positions from (a) are indicated. (a) (b) Figure 3.12 (a) Reduced-sphere BCC unit cell with the (110) plane. (b) Atomic packing of a BCC (110) plane. Corresponding atom positions from (a) are indicated.