Nuclear-polarization effect to the hyperfine structure in heavy   multicharged ions
  We have investigated the correction to the hyperfine structure of heavy multicharged ions, which is connected with the nuclear-polarization effect caused by the unpaired bound electron. Numerical calculations are performed for hydrogenlike ions taking into account the dominant collective nuclear excitations. The correction defines the ultimate limit of precision in accurate theoretical predictions of the hyperfine-structure splittings. 
A.V. Nefiodov, G. Plunien, G. Soff