Nuclear deformation effects on the binding energies in heavy ions are investigated. Approximate formulas for the nuclear-size correction and the isotope shift for deformed nuclei are derived. Combined with direct numerical evaluations, these formulas are employed to reanalyze experimental data on the nuclear-charge-distribution parameters in ${}^{238}\text{U}$ and to revise the nuclear-size corrections to the binding energies in H- and Li-like ${}^{238}\text{U}$. As a result, the theoretical uncertainties for the ground-state Lamb shift in ${{}^{238}\text{U}}^{91+}$ and for the $2p_{1/2}-2s$ transition energy in ${{}^{238}\text{U}}^{89+}$ are significantly reduced. The isotope shift of the $2p_j-2s$ transition energies for ${{}^{142}\text{N}\text{d}}^{57+}$ and ${{}^{150}\text{N}\text{d}}^{57+}$ is also evaluated including nuclear size and nuclear recoil effects within a full QED treatment.

• Received 30 November 2007

DOI:https://doi.org/10.1103/PhysRevA.77.032501