A crystal is made of particle X,Y and Z. X forms FCC packing, Y occupies all octahedral voids of X and Z occupies all tetrahedral voids of X, if all the particles along one body diagonal are removed then the formula of the crystal would be –
XYZ2
X2YZ2
X8Y4Z5
X5Y4Z8
When all particles along the body diagonal are removed, these 2 X atoms from the corner are removed, one Y particle removed & 2 Z particles are removed.
Hence new arrangement, X particle
Y particle = 4 -1=3
Z particle = 8 - 2=6
Hence formula =
Correct option is 4.