What are coordination number (nearest neighbour) in a SCC at distance of it lattice parameter (a) and next nearest neighbour at distance (a√2) and next to next nearest neighbour at distance (a√3) ?.

Coordination Number:

(1) The nearest neighbour distance is just the lattice parameter (a) therefore coordination number for a given atom in SCC unit cell is 6 (six).

(2) The next nearest neighbour are 12 at distancea/root 2 (each face diagonal in x ,y and Z plane).

(3) 3^rd neighbour (Next to Next nearest neighbour) are(8) at distance a root 3 (each corner along body diagonal.