Cubic Close Packing. Closest packed means that the atoms are packed together as closely as possible. The FCC unit cell is actually made of four cubic close packed layers (click to show the unit cell with layers). The first layer of atoms pack together as close as possible.

What is the another name of cubic close packing?

They are called face-centered cubic (FCC) (also called cubic close packed) and hexagonal close-packed (HCP), based on their symmetry.

What is cubic close packing class 12?

This crystal structure is called the structure of cubic close-packed (ccp) or face-centered cubic (fcc). In each of them, since each sphere is in contact with twelve spheres, the coordination number is 12. In these kinds of close packing, 74% of the space in the crystal is packed.