Class 12th "SOLID STATE"

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CRYSTAL SYSTEMS
There is seven types of Crystal system:

1. Cubic 
2. Tetragonal
3. Orthorhombic
4. Monoclinic
5. Triclinic
6. Hexagonal
7. Rhombohedral or Trigonal

"Crystal systems are defined based on 'Parameters' of a Unit cell : 
A unit cell is characterized by six parameters. 
a, b, c = edge length
alpha, beta, gama = angles

• Alpha(L) : angles lies between edges b & c. 
• Beta(B) : angles lies between edges a & b. 
• Gama(Y) : angles lies between edges a & b. 
Parameters are in various Crystal system : The following chart are defined that parameters of various Crystal system. 

Variations within a Crystal System:
Following types of variations we can see in the Crystal system. 

A. Primitive Unit Cells/Simple Unit Cell(PC or SC) 

B. Body-Centred Unit Cell(BCC) 
 
C. Face-Centred Unit Cell(FCC) 

D. End-Centred Unit Cell(ECC) 

                        THANK YOU ! 

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