A novel index for the description of molecular linearity

To investigate the description of molecular shape, a heterogeneous data set of 200 compounds was designed. The compounds included many disparate molec ular shapes, and a total of 64 descriptors was calculated including topolog ical indices, surface areas, molecular volumes, measures of molecular dimen sions, and ratios of moments of inertia. Cluster analysis on the variables indicated that there are four major categories of steric descriptors, those for molecular bulk, dimensions, and two clusters representing varying aspe cts of shape. To describe molecular shape more efficiently, a novel lineari ty index based upon ratios of moments of inertia and the molecular weight i s proposed.