Dynamic Polarizabilities and Other Dipole properties of Helium-Like Ions

The static and dynamic polarizabilities and the various oscillator strength sums are calculated for helium-like iso-electronic ions from Li + through Ne 8+ . The perturbation variation technique is used and Clementi's 4ζ wave functions are employed for the ground state wave functions. The oscillator strength sums S ( k ) in the length and the velocity forms agree with each other except for the case of S (2). It is found that the static polarizabilities are approximately proportional to (atomic number) -4.4 . The atomic number dependence of the dynamic polarizabilities is also discussed.