The crystal structure is formed by repeating arrangements of atoms or molecules in a lattice structure. There are 7 crystal systems defined by the length of the lattice axes (a, b, c) and interfacial angles (α, β, γ). The cubic system has equal lattice lengths (a = b = c) and 90 degree angles, while the triclinic system has unequal lengths and non-90 degree angles. The basis refers to the identical assembly of atoms that repeats in the lattice.

1. CRYSTAL STRUCTURE

2. ATOMIC ARRANGEMENT

3. SPACE LATTICE

4. SPACE LATTICE -3D

5. crystal structure
 The crystal structure is formed by associating every lattice point with an
assembly of atoms or molecules or ions,
 which are identical in composition, arrangement and orientation, is called
as the basis.
 The atomic arrangement in a crystal is called crystal structure.

6. BASIS

7. CRYSTAL SYSTEMS

8. BRAVAIS LATTICE

9. S.No. Crystal
System
Axial Lengths
(a, b, c)
Interfacial angles
(α, β, ɤ)
Example
1. Cubic a = b = c α = β =ɤ = 90o Iron, copper, CaF2, NaCl
2. Tetragonal a = b ≠ c α = β = ɤ = 90o
Ordinary
white tin, Indium
3. Orthorhombic a ≠ b ≠ c α= β= ɤ= 90o Sulphur,
Topaz
4. Monoclinic a ≠ b≠ c α = β = 90o ɤ ≠90o Na2SO4, FeSO4
5. Triclinic a ≠b ≠ c α ≠β ≠ ɤ ≠90o CuSO4, K2Cr2O7
6. Rhombohedral a = b = c α = β = ɤ ≠90o Calcite
7. Hexagonal a = b≠ c α = β = 90oɤ= 120o Quartz, Tourmaline
TYPES OF CRYSTAL SYSTEM

10. CUBIC

11. TETRAGONAL

12. ORTHORHOMBIC

13. MONOCLINIC

14. RHOMBOHEDRAL/HEXAGONAL/TRICLINIC

15. RHOMBOHEDRAL/HEXAGONAL/TRICLINIC