Question

Tetragonal crystal system has the following unit cell dimensions:

• A. \( a = b = c \), \( \alpha = \beta = \gamma = 90^\circ \)
• B. \( a = b = c \), \( \alpha = \beta = \gamma = 120^\circ \)
• C. \( a = b \neq c \), \( \alpha = \beta = 90^\circ \)
• D. \( a \neq b \neq c \), \( \alpha = \beta = \gamma = 90^\circ \)

Hint:

In the tetragonal crystal system, two axes are equal, and all angles are 90°.

Answer 1

The Correct Option is C

Step 1: Understand the unit cell dimensions.
In the tetragonal crystal system, two of the axes have equal lengths, and the angles between all axes are 90°.
Step 2: Conclusion.
Thus, the correct unit cell dimensions are \( a = b \neq c \), and the angles \( \alpha = \beta = 90^\circ \).
Final Answer: \[ \boxed{C} \]