ABSTRACT
This chapter discusses liquids as being structurally intermediate between solids and gases. Hydrogen bonding is of special importance in discussing organic liquids, and also the most precious liquid, water. Of more fundamental significance in the study of liquids is a function closely related to the radial distribution function known as the radial density function n(r). This function charts local variations in the average density of the substance as a function of distance from the centre of a molecule. Many substances that form liquids around room temperature are organic in nature and have molecules that are not in the least spherical. The model of liquids, known generally as the cell model, is an attempt to develop a near universal model of liquids. It assumes that each molecule is constrained by its neighbours into a ‘cell’ of roughly atomic dimensions: this is certainly the case in real liquids. The dynamics of liquids formed from non-spherical molecules is complex than the simple liquids.
