Question

A compound formed by elements $A$ and $B$ crystallises in the cubic structure where $A$ atoms are at the corners of the cube and $B$ atoms at the centre of the cube. What is the formula of the compound?

Answer 1

A atoms occupies corner of the unit cell. There are 8 corners and contribution of each corner is $\frac{1}{8}$. Therefore total A atoms is $8\times \frac{1}{8}=1$.

B atoms occupies centre of the cube. Therefore total B atm is 1. The formula is $AB$.