Isotope Shifts in Beryllium-, Boron-, Carbon-, and Nitrogen-like Ions   from Relativistic Configuration Interaction Calculations
  Energy levels, normal and specific mass shift parameters as well as electronic densities at the nucleus are reported for numerous states along the beryllium, boron, carbon, and nitrogen isoelectronic sequences. Combined with nuclear data, these electronic parameters can be used to determine values of level and transition isotope shifts. The calculation of the electronic parameters is done using first-order perturbation theory with relativistic configuration interaction wave functions that account for valence, core-valence and core-core correlation effects as zero-order functions. Results are compared with experimental and other theoretical values, when available. 
C. Naz\'e, S. Verdebout, P. Rynkun, G. Gaigalas, M. Godefroid and P.   J\"onsson
physics.atom-ph