Molecular properties spherical index

Liquid Phase Calculations of the Linear Response. The data in Table 5 for the isotropic polarizability, derived formally via the Lorentz-Lorenz equation (1) from the measured refractive index, shows that the assumption that individual molecular properties are largely retained at high frequency in the liquid is very reasonable. While the specific susceptibilities for the gas and liquid phases differ, once the correction for the polarization of the surface of a spherical cavity, which is the essential feature of the Lorentz-Lorenz equation, has been applied, it is clear that the average molecular polarizabilities in the gas and liquid have values which always agree within 5 or 10%. 

The ovality index O is an anisometry descriptor, i.e. a measure of the departure of a molecule from the spherical shape, based on the property that, for a fixed volume, the spherical shape presents the minimum surface [Bodor et al, 1989 Bodor et al, 1998]. It is calculated from the ratio between the actual molecular surface area SA and the minimum surface area SAq corresponding to the actual molecule van der Waals volume... 

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