packing of constituent particles inside lattice in such a way that they occupy maximum available space in the lattice is known as Close Packing.Types of close packing, zeolite,intercalation compound..

1. CLASSIFICATION
BASED ON
PACKING IN
CRYSTALS

2. PACKING IN CRYSTALS
Arrangement of
constituents(atoms/ions/molecules)in
crystals

3. TYPES OF PACKING IN CRYSTALS
Linear Arrangement
Two dimensional close packings
Hexagonal closed packing(hcp)
Cubical closed
packing(ccp)or(fcp)
Body centered cubic(bcc)

4. LINEAR ARRANGEMENT OF SPHERES IN ONE
DIRECTION
 In a specific direction, there is only one possibility to
arrange the spheres in one direction.
 Each sphere is in contact with two neighbouring
spheres on either side.

5. TWO DIMENSIONAL CLOSE PACKING
 AAA… TYPE:
Linear arrangement of spheres in one direction
is repeated in two dimension.
All rows are identical as the first one. It is also
called square close packing.

6. ABAB… TYPE:
 In this type, the second row spheres are arranged
in such a way that they fit in the depression of the
first row.
 It is also known as hexagonal close packing.
 Each sphere is surrounded by six other nearest
spheres, hence its CN = 6

7. HEXAGONAL CLOSE PACKING(HCP)
 ABAB…. Arrangement
 CN = 12

8. HEXAGONAL CLOSED PACKING(HCP)
 This structure has the stacking sequence of
different layers of spheres as ABAB…..
 A close examination of this arrangement of different
layers of spheres shows that it has hexagonal close
packing symmetry, hence this arrangement is called
hexagonal close packed structure(hcp)
 In this structure, each sphere is surrounded by 12
other nearest spheres, hence the coordination
number of each sphere is 12
 Example: Cobalt(Co), Camium(Cd), Zinc(Zn)

9. FACE CENTERED CUBIC
PACKING(FCC)

10. FACE CENTERED CUBIC(FCC) OR (CCP)
 This structure has the stacking sequence of
different layers of spheres such as ABC ABC..
 In this structure, each sphere is surrounded by 12
other nearest spheres, hence the coordination
number of each sphere is 12.
 Example: Aluminium(Al), Copper(Cu), Gold(Au)

11. COMMON FEATURES OF HCP AND CCP:

12. COMMON FEATURES OF HCP & CCP
 Coordination number of each sphere is 12
 Each sphere is surrounded by 6 nearest spheres
lying in the same layer, 3 spheres lying in the layer
just above and 3 spheres lying in the layer just
below it.
 Both types have same packing efficiency. 74% of
the total volume of unit cell is occupied by the
spheres.

13. BODY CENTERED CUBIC(BCC)

14. BODY CENTERED CUBIC(BCC)
 In this arrangement, the pattern ABAB is repeated
throughout the crystal.
 Each sphere has a coordination number of 8, four
neighbours in the layer above and four in the layer
below.
 Example: Barium(Ba), Sodium(Na),
Titanium(Ti), Tungsten(W), Zironium(Zr)

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