Question

Which of the following primitive unit cells have none of their edge lengths equal i.e. $a\ne b\ne c$?

• A. Monoclinic
• B. Triclinic
• C. Orthorhombic
• D. All of the above.

Answer 1

The correct option is D All of the above.

For Monoclinic:
$a\ne b\ne c\alpha =\gamma ={90}^{\circ },\beta \ne {90}^{\circ }$

For Triclinic:
$a\ne b\ne c\alpha \ne \beta \ne \gamma ={90}^{\circ }$

For Orthorhombic:
$a\ne b\ne c\alpha =\beta =\gamma ={90}^{\circ }$