[en] This paper reports on the molecular information needed to calculate any macroscopic equilibrium property, such as pressure or free energy, using standard statistical thermodynamic relationship. Various transport properties, such as the self-diffusion coefficient of small electrolyte ions, and spectroscopic variables, such as the average NMR relaxation rate of probe nuclei in a solute species, also can be calculated from pertinent radial distribution functions. Thus, for theoretical calculations of the measurable properties of liquid solutions, radial distribution functions provide a basis whose broad utility resembles that of the wave function in quantum mechanical calculations. However, radial distribution functions are not the ultimate origin, but rather the most useful and general microscopic counterparts, of macroscopic properties that also reflect interparticle interactions