Question

give a relationship between nearest neighbour distance(d),radius of atom(r), edge of unit cell(a), for fcc and BCC crystal

Answer 1

Simple cubic - Nearest  dist - a,  radius a/2   , z(no of atoms per unit cel)  = 1 Fcc -  Nd = a/(2)1/2     , radius  = a/2 root2   z=4 Bcc-  Nd- a root 3 /2   ; radius = a root3 /4    z= 2Read more on Sarthaks.com - https://www.sarthaks.com/251596/give-relationship-between-nearest-neighbour-distance-radius-atom-edge-unit-cell-crystal