Profiles of the Fe ii 6147.7 and 6149.3 Å lines in the spectra of HgMn stars. The observed spectra are offset vertically for clarity. The unshifted spectra show theoretical calculations for 2.5 kG radial (dashed line) and turbulent (solid line) magnetic field. The dash-dotted line corresponds to non-magnetic theoretical spectrum. The vertical dotted lines indicate central wavelengths of the Fe ii lines. The bottom plot schematically illustrates the Zeeman splitting patterns of the two Fe ii lines.