## 3 Conclusions  
From the present results and discussion, the following conclusions can be drawn:  
1. The determined atom polarizabilities are suitable for calculating reasonably accurate molecular polarizabilities of polyatomic molecules and, probably, have greater validity in general than additive values for calculating interactions among atoms in molecules. The anisotropies of a wide variety of polyatomic molecules can be largely attributed to atom dipole interactions, in support of [PERSON]'s [1-3] and [PERSON]'s [4] suggestions. The variety of molecular properties, which can be accounted for, at least approximately suggests that the atom-dipole interaction model is a reasonable facsimile of real molecules. The model is appealing because it requires relatively little information for practical calculations. It is to be expected that further research on the model will deal to refinements and extensions to other properties; _e.g._, the theory has been extended to include effects because of the nonlinear response of atoms to an applied field, and to consider the role of higher multipole interactions in optical rotation. Both of these developments may well have significant effects on the properties discussed in this report. Even if one is interested in only the dipole response of the system, which is expressed by appropriate elements of the \(\mathbf{A}^{-1}\) matrix, that response is influenced by all orders of multipole response, by virtue of the dependence of each element of \(\mathbf{A}^{-1}\) on all elements of \(\mathbf{A}\).  
2. A _hypothesis_ is indispensable for a suitable representation of polarizability derivative, without which the registered variations will be of opposite sign to the experimental magnitudes.  
3. The point-atom model is not only a mathematical approximation for real molecules, but also a well-defined system, whose behaviour can be calculated to a high degree of accuracy on the basis of known physical laws. Where the behaviour of a real molecule is similar to that of the model, an insight is gained into the origins of the behaviour. Where discrepancies, _e.g._, resonances, are found, it can be concluded that the molecule is not like the model.  
4. The results of the present work clearly indicate that, because of the observed differences between the molecular polarizability results of our program POLAR and our version of program PAPID, it may become necessary to recalibrate POLAR. The values calculated with POLAR are quite larger than those obtained with the reference program PAPID, and POLAR polarizability values do not increase monotonically with bond distances. The recalibration means to obtain better atomic polarizabilities to start with in Equation (13). It appears that the results of good-quality _ab initio_ calculations might be suitable as primary standards for such a calibration.  
Work is in progress on the recalibration of POLAR. The difference between POLAR polarizability and PAPID polarizability results is because of the different parametrization schemes used for the initial atomic polarizabilities. PAPID uses atomic polarizability values fitted to high-quality calculations, while POLAR performs a simpler individual computation for each molecule, in order to exploit the difference among different atoms in different functional groups in different molecular environments.