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Bravas Mattemalica a

Total Axial distancce or edge length Crysta Space or system Minimum symmetry elements Axial angles Examples Bravais lattices Bravais lattices Cubic Primitive Body-centred Face-centred | a = b = c | = = = 90 | 4 three-fold 3 four-fold NaCl, KCI ZnS, diamond, Cu Ortho rhombic Primitive Body-centred Face-centred End-centred | Three mutually perpendicular 2-fold (or) 2-axis l four-fold axis of symmetry = - = 90 Rhombic sulphur, KNO, BaSO4, K2S TetragonPrimitive -B-y | White Sn. SnO2 TiO,, CaSO NH4Br 90 Body-centred

Monoclinic Primitive = =90 P 90 Monoclinic sulphur, Na,SO, 10H2O CaSO42H2O 1 two-fold axis of symmetry end-centred Triclinic Primtive of symmetry l six-fold axis | a=b c of symmetry 1 three-fold axis of symmetry Graphite, ZnO CdS Hexagonal Primitive = 120 o Y90 Calcite (CaCO), Rhomo- bohedral or Trigonal Primitive HgS (cinnabar), NaNO,, ICl 39 Total 14

i. Primitive ii. End-centered iii. Body-centered iv. Face-centered 2. Orthorhombic: unequal sides, angles between faces all 90

i. Primitive i. Body-centered 1. Face-centered (or simple) 1. Cubic: All sides of same length between faces are all 90

i. Primitive ii. Body-centered 3. Tetragonal: one side different in length to the other, two angles between faces all 90

More than 90 Less than,'2o 90 i. Primitive ii. End-centered 4. Monoclinic: one side different in length to the other, only two angles between faces are 90

120 less than 90 90 2 0a ls 5. Triclinic: unequal sides a, b, c, and A, B, C are unequal angles as well as non-equal to 90 6. Hexagonal: one side different in length to the other two, the marked angle two faces are 120 7. Rhombohedral: All sides of equal length, only angles on two faces are 90