Molecular volumes and densities of liquids and solids by molecular mechanics?estimation and analysis

Molecular volumes of 80 compounds (50 liquids and 30 solids), with densities in the range 0·6–3·0 g cm−3, were calculated by molecular mechanics. The densities derived from these molecular volumes (Vmol MM) by the approximation dMM = mol. wt/Vmol MMNA (NA = Avogadro's number) give two linear correlations (one for liquids and one for solids) when plotted versus experimental densities. Two general equations obtained from those relationships give a good precision (3% mean error) when tested in the calculation of the experimental densities of 183 compounds that have different structures and functional groups.