  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.
