Change in the Ca HK line splitting with increasing (uniform) magnetic field. Under 1 MG the components are still recognizable, but this changes drastically until the field is above 7 MG. After that point, the components are grouped into three groups: the π component in the middle and the σ± on both sides.
Spectrum on the left, with the initial spectrum without magnetic splitting in dotted line, and relative intensity of the components in red ticks. On the right, the evolution of the different components with the magnetic field, and the current field strenght in red.