Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. Why is coordination number of HCP is 12? In this, one particle is attached to 6 at the same layer & 3 to the above and below layer.Thus a total of 12. Coordination number in Bcc and simple.

Coordination Number Of Hcp Youtube

If you look at the figure below, you might think that hexagon close-packed crystal structure is more complicated than face-centered cubic crystal structure. In fact, it is a simpler structure.

Think back to the last section where we constructed first one layer of atoms and then a second layer of atoms for face-centered cubic structure. Now, for hexagonal close-packed crystal structure, we do not construct a third layer. Instead, the third layer is simply the first layer repeated, the fourth layer is the second layer repeated, and so on and so on as shown in the figure below.

It turns out that face-centered cubic and hexagonal close-packed crystal structures pack atoms equally tightly. Some metals with hexagonal close-packed crystal structures include cobalt, cadmium, zinc, and the α phase of titanium. A more typical representation of the hexagonal close-packed structure is shown in the figure below. In this representation a hexagon on the top and on the bottom sandwich a triangle in between the two hexagons.

1. HCP is one of the most common structures for metals. HCP has 6 atoms per unit cell, lattice constant a = 2r and c = (4√6r)/3 (or c/a ratio = 1.633), coordination number CN = 12, and Atomic Packing Factor APF = 74%. HCP is a close-packed structure with AB-AB stacking.
2. The coordination number of the atoms in this structure is 12. There are six nearest neighbors in the same close packed layer, three in the layer above and three in the layer below. The packing factor is 0.74, which is the same as the fcc unit cell.
3. Co-ordination number in hcp structure is 1 2.The hexagonal closest packed (hcp) has a coordination number of 12 and contains 6 atoms per unit cell. A is correct option.

Coordination Number Of Hcp Youtube

Coordination Number Of Hcp In 3d

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