Variation method helium application

This paper reviews progress in the application of atomic isotope shift measurements, together with high precision atomic theory, to the determination of nuclear radii from the nuclear volume effect. The theory involves obtaining essentially exact solutions to the nonrelativistic three- and four-body problems for helium and lithium by variational methods. The calculation of relativistic and quantum electrodynamic corrections by perturbation theory is discussed, and in particular, methods for the accurate calculation of the Bethe logarithm part of the electron self energy are presented. The results are applied to the calculation of isotope shifts for the short-... 

Section 19.1 The Variation Method and Its Application to the Helium Atom... 

An application of the variation method to the lithium atom ground state uses an orbital wave function containing hydrogen-like orbitals with variable orbital exponents (effective nuclear charges) similar to that used with helium, except that different effective... 

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