  We have systematically investigated the ground-state hyperfine structure for
alkali-metal atoms ^{87}Rb, ^{133}Cs, ^{211}Fr and alkali-metal-like ions
^{135}Ba^+, ^{225}Ra^+, which are of particular interest for parity violation
studies. The quantum electrodynamic one-loop radiative corrections have been
rigorously evaluated within an extended Furry picture employing core-Hartree
and Kohn-Sham atomic potentials. Moreover, the effect of the nuclear
magnetization distribution on the hyperfine structure intervals has been
studied in detail and its uncertainty has been estimated. Finally, the
theoretical description of the hyperfine structure has been completed with full
many-body calculations performed in the all-orders correlation potential
method.
