Question

Square packed sheets are arranged on the top of other such that a sphere in the next layer rests on the centre of a square in the previous layer. Identify the type of arrangement and find the coordination number.

Answer 1

Dear student,

The centers of the spheres lie one below another. This type of arrangement is called square close packing. In such packing one sphere touches four other spheres. In this case 52.4% of the volume is occupied. The remaining 47.6% of the volume is empty and is called void volume.
Coordination no. = 4 (in 2D) and 6 (in 3D)

Regards.