EMIR K-band nuclear spectra of the QSO2s showing the emission lines detected. The spectra were scaled in the Y-axis with the purpose of better visualization and smoothed using a 10-pixel boxcar. The spectra of the QSO2s are displayed from top to bottom in order of increasing redshift. Vertical dashed black lines indicate the position of the atomic lines, and dotted lines indicate the H₂ lines.