Data for: Using the molecular rotational motion concept within the framework of the "structure-property" problem to predict the volume expansion coefficients and densities of liquids

Тhe rotational motion of molecules in the liquid phase has been shown to be the main factor that determines the liquid’s thermal expansion and can be used for its calculation; it is also one of the main factors determining the densities of liquids in general. This study establishes that not only the thermal expansion temperature coefficient but also the densities are grouped in sequences depending on the functional class of compounds. The correlations in this case are much coarser and more fragmented, in contrast to homologous series. The general hydrocarbon sequence breaks down into separate sequences according to their functional groups, such as saturated or aromatic hydrocarbons. In these cases, the density of the liquid depends not only on the rotational state of the molecules but also on the density of the substance of the molecule. The rotational moments of inertia J can be considered the main descriptors of the molecular spatial structure in addition to the topological descriptors, as they show the mass distribution along the three main rotation axes. Thus, it is shown that the thermal expansion of liquids with an average size of molecules, in temperatures where molecules do not complete full rotations, is mainly due to the entropy of the rotational motion.