Electron correlation effects in hyperfine interactions in 45Sc and 89Y

Relativistic coupled-cluster theory has been employed to calculate the magnetic dipole and electric quadrupole hyperfine structure constants for the stable isotopes 45Sc and 89Y. The results are in good agreement with available experimental data. The role of electron correlation is found to be important. The trend exhibited by these effects in the systems under consideration with d-valence electrons is rather different from previously studied s and p single valence atomic systems. The contributions of certain higher order correlation effects are about 10–20%. Electric quadrupole hyperfine structure constants for 4d2D3/2 and 4d2D5/2 states are presented for the first time.