MODELING OF THE LONG-RANGE PART OF THE INVARIANTS OF THE INCREMENTAL PAIR POLARIZABILITY TENSOR DELTA(ALPHA)OVER-CAP

The long-range part of the incremental pair polarizability tensor DELTAalpha can be described by reaction field theory. However, calculation of DELTAalpha usually requires complete knowledge of the static linear dipole and higher polarizabilities as well as of the linear and nonlinear polarizabilities at imaginary frequencies. Since especially the latter quantities are hardly available at present, a simple but successful approach is given for the invariants of DELTAalpha in terms of the Cauchy moments S(-2) and S(-4), which are known for many atoms and small molecules with high precision from the dispersion of the mean linear dipole polarizability alpha(omega).