What are unit cells, and how do you determine the number of atoms in one of them?
The unit cell is the most primitive 3D structure that contains the arrangement of atoms which form the crystal of a compound. The unit cell is probably most meaningful in the study of minerals, so it is more of an inorganic analytical technique rather than an organic analytical technique. There are 7 3D crystal lattice systems which form 14 primitive 3D forms called the Bravais lattices. The 14 Bravais lattices can be further subdivided into 32 point groups.