Precision Calculations of Atomic Polarizabilities: A Relevant Physical Quantity in Modern Atomic Frequency Standard

Electric dipole polarizabilities of atoms are very important in many different physical applications, such as the precision atomic frequency standard. Calculations of these properties are very important and challenging. We propose a calculation strategy to calculate the frequency dependent dipole polarizabilities with high precision variationally by using a set of high quality orbital bases where the electron correlations can be taken into account adequately. The static polarizabilities of the ground state of Na are calculated accurately by such a method and can be compared with precision experiment measurement directly. The calculation result is in excellent agreement with the available experimental measurements within about 0.1%, which demonstrates the validity of our strategy. Our calculation strategy has a wide usage, not only in polarizibilies, but also in other fields such as theoretical treatment of electron-atom scattering processes. Using the same orbital bases, we carry out precision calculation of Na^- affinities. Our calculated affinity is in excellent agreement with precision laser spectroscopy measurements within 0.1%.