Question

In Rutile $\left(Ti{O}_2\right)$ structure, If the number of an effective number of molecules in each unit cell is $x$ and coordination number of oxygen in each unit cell is $y$ what is the value of $x+y$?

In the figure given about red balls represents oxygen atoms and blue balls represents titanium atoms :

• A. 4
• B. 6
• C. 5
• D. 8

Answer 1

The correct option is C 5

Effective number of titanium atoms per unit cell $=8\times \frac{1}{8}+1=2$
Effective number of oxygen atoms per units cell $=2+4\times \frac{1}{2}=4$
So, effective number of molecules per units cell $\left(x\right)=2$ and co-ordination number of oxygen atom $\left(y\right)=3$
So, $x+y=5$