Question

The lattice parameters for a monoclinic crystal are:

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

Hint:

Monoclinic has three unequal edges and exactly two right angles.

Answer 1

The Correct Option is A

Run through crystal systems: cubic (D), tetragonal, orthorhombic, monoclinic (matches A: a≠b≠c, alpha=gamma=90≠beta), triclinic (C), hexagonal, rhombohedral. Only A matches monoclinic.

\[\boxed{a \neq b \neq c,\ \alpha = \gamma = 90^\circ}\]