Energies of the magnetic f states associated with the 4s²S_1/2 (upper left panel), (upper right panel), and (the two lower panels) FS levels of K I, relative to their corresponding baricenters. A range of magnetic field strengths between 0 and 200 G is selected in all panels except the lower left, in which a smaller range is displayed to highlight various level crossings. The colors of the curves indicate the magnetic quantum number f of each state, including −3 (purple), −2 (blue), −1 (green), 0 (black), 1 (yellow), 2 (orange), and 3 (red).