Question

The crystal system of a compound with unit cell dimensions $a = 0.387\, nm$, $b = 0.387\, nm$ and $c = 0.504 \,nm$ and $\alpha = \beta = 90^{\circ}$ and $\gamma$ = $120^{\circ}$ is

• A. cubic
• B. hexagonal
• C. orthorhombic
• D. rhombohedral

Answer 1

Answer: (B)

hexagonal

Answer 2

When $\alpha = \beta \neq c, \alpha = \beta = 90^{\circ}, \gamma = 120^{\circ}$. The given condition is characteristic of hexagonal system.