1. Unit cell - Unit cell is the most basic and least volume consuming repeating structure of any solider words the smallest three dimensional unit of a lattice which when repeated in three dimensions generates the entire lattice is called the unit cell.
It is used to visually simplify the crystalline patterns solids arrange themselves in. When the unit cell repeats itself, the network is called a lattice.
E.g. Cubic unit cell
2. Coordination number is the number of atoms, ions, or molecules that the central atom or ion of a coordination compound holds as its nearest neighbours in the complex. So, it is the number of immediate neighbours of the atom in that crystal. Coordination number is also called ligancy.
To explain this we take some examples of coordination compounds. Mo and Cr has coordination number 8 in the coordination complexes [Mo(CN)8]4- and [Sr(H2O)8]2+. Zr has coordination number 7 in the complex [ZrF7]3-.
Rate this question :