Seven Primitive Unit Cells and their Possible Variations as Centred Unit Cells - 12th class

Seven Primitive Unit Cells and their Possible Variations as Centred Unit Cells - 12th class chemistry

Crystal system	Possible variations	Axial distances or edge lengths	Axial angles	Examples
Cubic	Primitive, Body-centred, Face-centred	a= b = c	𝝰 = 𝝱 = γ = 90°	NaCl, Zinc blende, Cu
Tetragonal	Primitive, Body-centred	a = b  ≠ c	𝝰 = 𝝱 = γ = 90°	White tin, SnO₂,TiO₂, CaSO₄
Orthorhombic	Primitive, Body-centred, Face-centred, End-centred	a ≠  b  ≠ c	𝝰 = 𝝱 = γ = 90°	Rhombic sulphur, KNO₃, BaSO₄
Hexagonal	Primitive	a = b  ≠ c	𝝰 = 𝝱 = 90° γ =120°	Graphite, ZnO, CdS
Rhombohedral or Trigonal	Primitive	a= b = c	𝝰 = 𝝱 = γ ≠ 90°	Calcite(CaCO₃), HgS (cinnabar)
Monoclinic	Primitive, End-centred	a ≠  b  ≠ c	𝝰 = γ = 90° 𝝱  ≠ 90°	Monoclinic sulphur, Na₂SO₄.10H₂O
Triclinic	Primitive	a ≠  b  ≠ c	𝝰 ≠ 𝝱  ≠ γ ≠ 90°	K₂Cr₂O₇, CuSO₄, 5H₂O,H₃BO₃