Question

Name the parameters which are characteristics of the unit cell.

Answer 1

In the given question the parameters which are responsible for a unit cell has been asked. A unit cell is a portion of crystal lattice which on repetition leads to the structure of crystal. So there are a total of two parameters which represent the unit cell.

Complete step-by-step answer: A unit cell is the smallest repeating unit in space lattice which when repeated over and over again in different directions produces complete crystal lattice. A unit cell is characterized by the following two basic parameters and these parameters are as follows.
The first parameter by which the unit cell is characterized is through its lengths or dimensions followed by the three edges that are A, B and C. These edges may or may not be equally perpendicular.
And the second parameter is the interaxial angles between the pair of edges, $\alpha$which occur between B and C, $\beta$ which occur between A and C and$\;\gamma$ which occur in between A and B as shown in the diagram below. Thus, a unit cell is characterized by six parameters in total two categories and they are $a,{\text{ }}b,{\text{ }}c,{\text{ }}\alpha ,{\text{ }}\beta ,{\text{ }}\gamma .\;$which are shown in the diagram below:

Therefore, the Angles between the edges are characterized by alpha, beta and gamma. So, the alpha, beta and gamma are the opposite angle of side A, B and C respectively.

Note: In short, we can say that the parameters which are the characteristics of unit cell
are first Axial distances or edge lengths and second Axial angles. So, the six parameters that characterize a unit cell whereas the unit cell has all the characteristics of a crystal lattice. The unit cell is characterized by three distances along the three edges of the lattice and the angles between them.