Question

Tetragonal crystal system has the following unit cell dimensions.

• A. $a=b=c$ and $\alpha =\beta =\gamma ={90}^{\circ }$
• B. $a=b\ne c$ and $\alpha =\beta =\gamma ={90}^{\circ }$
• C. $a\ne b\ne c$ and $\alpha =\beta =\gamma ={90}^{\circ }$
• D. $a=b\ne c$ and $\alpha =\beta ={90}^{\circ },\gamma ={120}^{\circ }$

Answer 1

The correct option is B $a=b\ne c$ and $\alpha =\beta =\gamma ={90}^{\circ }$

Tetragonal crystal system has the following unit cell dimensions

$a=b\ne c$ and $\alpha =\beta =\gamma ={90}^{\circ }$

The lengths of the two sides are equal and different from the length of the third side. All the three angles are equal to ${90}^{\circ }$.

Thus, option (B) is the correct answer.