Concept of a Molecular System, Molecular Unit, and Molecular Material
All materials have their own intrinsic function which might be useful for human society. In most materials, it is usually their bulk properties which are utilized. The concept of a molecular system is derived from the understanding that the functionality of materials is based on the properties of their component molecules. The overall function of a material is the combined effect of the functions of each component molecule, and these component molecules are defined as molecular units.