Question

What are the voids commonly found in close-packed structures?

Answer 1

The voids commonly found in close-packed structures are

1. Tetrahedral voids:
   • When four spheres arrange in a tetrahedral pattern, they form smaller voids. 
   • Three closely packed spheres in the lower layer form a triangular depression where a sphere from the upper layer sits.

   • For every one atom, there are two tetrahedral voids in a close-packed structure.

2. Octahedral voids:
   • They are larger and formed when six spheres surround an empty space.
   • The formation occurs when two triangular depressions from adjacent layers of spheres overlap each other.
   • For every one atom, there is one octahedral void.