An hexagonal close packing crystal lattice has Options: A Same coordination number as of simple primitive - Chemistry - Solid State

Question

An hexagonal close packing crystal lattice has
Options:

A

Same coordination number as of simple primitive lattice

B

Same type of voids as of body centered cubic lattice

C

Same ratio of atoms and voids as of face centered cubic
lattice

D

All of these

Balaram Shil · Accepted Answer

Dear Student,

The hexagonal closest packed (hcp) has a coordination number of
12 and contains 6 atoms per unit cell
The face-centered cubic (fcc) has a coordination number of 12
and contains 4 atoms per unit cell
The body-centered cubic (bcc) has a coordination number of 8
and contains 2 atoms per unit cell
The simple cubic has a coordination number of 6 and contains 1
atom per unit cell

In the close packed crystals (FCC, HCP) there are two
types of voids ®
tetrahedral and octahedral
voids (identical in both the structures as the voids
are formed between two layers of
atoms)
There are 8 tetrahedral holes and 4 octahedral holes in a fcc unit
cell
There are 8 tetrahedral voids per cell and 4 octahedral voids per
cell in hcp

So answer is B

Regards,

An hexagonal close packing crystal lattice has Options: A Same coordination number as of simple primitive lattice B Same type of voids as of body centered cubic lattice C Same ratio of atoms and voids as of face centered cubic lattice D All of these

An hexagonal close packing crystal lattice has

Options:

A
Same coordination number as of simple primitive lattice

B
Same type of voids as of body centered cubic lattice

C
Same ratio of atoms and voids as of face centered cubic lattice

D
All of these