73 research outputs found
Theory and applications of atomic and ionic polarizabilities
Atomic polarization phenomena impinge upon a number of areas and processes in
physics. The dielectric constant and refractive index of any gas are examples
of macroscopic properties that are largely determined by the dipole
polarizability. When it comes to microscopic phenomena, the existence of
alkaline-earth anions and the recently discovered ability of positrons to bind
to many atoms are predominantly due to the polarization interaction. An
imperfect knowledge of atomic polarizabilities is presently looming as the
largest source of uncertainty in the new generation of optical frequency
standards. Accurate polarizabilities for the group I and II atoms and ions of
the periodic table have recently become available by a variety of techniques.
These include refined many-body perturbation theory and coupled-cluster
calculations sometimes combined with precise experimental data for selected
transitions, microwave spectroscopy of Rydberg atoms and ions, refractive index
measurements in microwave cavities, ab initio calculations of atomic structures
using explicitly correlated wave functions, interferometry with atom beams, and
velocity changes of laser cooled atoms induced by an electric field. This
review examines existing theoretical methods of determining atomic and ionic
polarizabilities, and discusses their relevance to various applications with
particular emphasis on cold-atom physics and the metrology of atomic frequency
standards.Comment: Review paper, 44 page
Low-energy resonance states upon electron capture by five-membered heterocycles and cyclopentadiene
Method for resolution of closely situated resonance peaks for the yield of negative ions based on the energy
Thermochemical determination of structure of negative ions on the basis of data from resonance electron capture mass spectrometry. 1. Heterocyclic analogs of cyclopentadiene
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