A magnetic field acting in a metal induces a transverse current, which is known as the classical Hall effect, while in some magnetic materials a transverse current exists even in the absence of an external magnetic field, known as the anomalous Hall effect. This effect originates from time-reversal symmetry breaking due to magnetic ordering and relativistic spin-orbit coupling, and recent studies have shown that it may exist in some antiferromagnetic materials. However, the origin of the anomalous Hall effect, and its connection to topology is complex and variable, and requires in-depth study of a wider range of systems. A team lead by Dr. Jakub ？elezny from Institute of Physics, Czech Academy of Sciences, Czech Republic, systematically investigated the anomalous Hall effect (AHE) in a large number of magnetic materials using automated DFT calculations. By building a large-scale database of reference intrinsic AHEs, the authors reveal the general properties of AHEs and provide insights into the relationship between AHE amplitude and spin-orbit coupling strengths, magnetization, and symmetry. The authors' study shows that the effect of symmetry in the AHE amplitude is more significant compared to the relationship between magnetization and spin-orbit coupling, especially in large AHE materials. In addition, the authors have investigated the dependence of AHE under magnetization rotation for some materials and found that the relationship between AHE and magnetization does not simply follow the common linear relationship, but is more influenced by the symmetry of the crystal structure. This finding reveals that the behavior of AHE may be more complex and cannot be simply described by a single formula. Although the authors' study focused on metallic materials, calculations were also performed on hundreds of insulators. The results show that these insulator materials do not exhibit the quantum anomalous Hall effect, and that large AHE amplitudes are very rare in the materials calculated, suggesting that there is some sort of practical limit to the AHE amplitude. Overall, this study provides insight into the understanding of the anomalous Hall effect, while also emphasizing the need for more experimental validation and further research to explain the complex AHE phenomenon. In addition, the authors have calculated the ordinary conductivity, which provides important information about the conductivity properties of the material, although in some ways slightly more limited than the results of the AHE calculations.