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

Answer 1

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

Compounds of the tetragonal crystal system are referred by the three mutually perpendicular axes. The two horizontal axes are of equal length, while the vertical axis is of a different length and may either be shorter or longer than the other two.

$a=b\ne c,\alpha =\beta =\gamma ={90}^o$