  We use a recently developed version of the configuration method for open
shells to study electronic structure of erbium and fermium atoms. We calculate
excitation energies of odd states connected to the even ground state by
electric dipole transitions, the corresponding transition rates, isotope shift,
hyperfine structure, ionization potentials and static scalar polarizabilities.
We argue that measuring isotope shift for several transitions can be used to
study nuclear deformation in even-even nuclei. This is important for testing
nuclear theory and for searching for the hypothetical island of stability.
Since erbium and fermium have similar electronic structures, calculations for
erbium serve as a guide to the accuracy of the calculations.
