In which of the following structures coordination number for cations and anions in the packed structure will be same? (i) Cl–ion form fcc lattice and Na+ ions occupy all octahedral voids of the unit cell. (ii) Ca2+ ions form fcc lattice and F- ions occupy all the eight tetrahedral voids of the unit cell. (iii) O2– ions form fcc lattice and Na+ions occupy all the eight tetrahedral voids of the unit cell. (iv) S2– ions form fcc lattice and Zn2+ ions go into alternate tetrahedral voids of the unit cell.
Option A) In NaCl, Cl− ion form fcc lattice and Na+ ions occupy all octahedral voids of the unit cell. The coordination number of both cation and anion here is 6
