Why should chemists care about band structure diagrams?
Thus far we have discussed molecular orbital (MO) diagrams in some detail. These describe the electronic energy levels of isolated molecules. As we have discussed they also can be used to approximate the energy levels in a solid. However, in a solid intermolecular (between neighboring molecules) interactions can also be important. In fact many interesting properties of solids such as metallic conductivity, superconductivity, magnetism, etc. depend crucially upon intermolecular interactions. The solid state equivalent to a MO diagram is called a band structure diagram. The band structure diagram contains information about both the bonding interactions within a molecule (intramolecular) and the intermolecular interactions. Chemists often refer to band structure diagrams as spaghetti plots, because or their appearance. However, the ability to understand band structure diagrams allows one to extract valuable information about a material: • Electronic conductivity • Optical properties • Sta
