  Three models of the nuclear magnetization distribution are applied to predict
the hyperfine structure of the hydrogenlike heavy ions and neutral thallium
atoms: the uniformly magnetized ball model and single-particle models for the
valence nucleon with the uniform distribution and the distribution determined
by the Woods-Saxon potential. Results for the hydrogenlike ions are in
excellent agreement with previous studies. The application of the Woods-Saxon
model is now extended to the neutral systems with the explicit treatment of the
electron correlation effects within the relativistic coupled cluster theory
using the Dirac-Coulomb Hamiltonian. We estimate the uncertainty for the ratio
of magnetic anomalies and numerically confirm its near nuclear-model
independence. The ratio is used as a theoretical input to predict the nuclear
magnetic moments of short-lived thallium isotopes. We also show that the
differential magnetic anomalies are strongly model dependent. The accuracy of
the single-particle models significantly surpasses the accuracy of the simplest
uniformly magnetized ball model for the prediction of this quantity. Skripnikov
[Skripnikov, J. Chem. Phys. 153, 114114 (2020)] has shown that the
Bohr-Weisskopf contribution to the magnetic dipole hyperfine structure constant
for an atom or a molecule induced by a heavy nucleus can be factorized into the
electronic part and the universal nuclear magnetization dependent part. We
numerically confirm this factorization for the Woods-Saxon single-particle
model with an uncertainty less than 1%.
