Question

How many number of molecules per unit cell which crystallizes in the form of face centred monoclinic lattice with a molecule at each lattice?

Answer 1

We have to find the number of molecules per unit cell which crystallizes in the form of face centered (monoclinic) lattice with a molecule at each lattice.

solution : according to Bravais lattice, there are only two monoclinic lattice exist.

1. primitive

2. base centered monoclinic.

we don't have face centered monoclinic but we have face centered orthorhombic.

now if your question is about base centered monoclinic, there are 2 molecular per unit cell.

8 molecules are located at the corner of cubic unit cell. we know, each corner is shared by eight cells.

and 2 molecules are located two base of monoclinic. and each base is shared by two cells.

now no of molecules per unit cell = 8 × 1/8 + 2 × 1/2 = 2

Therefore the no of molecules per unit cell of base centered monoclinic is 2.

[ note : no of molecules per unit cell of face centered orthorhombic is 4 ]

Answer 2

Answer:

Hope it help you

Have a good day