Abstract
The Zeeman patterns for 14N pure quadrupole resonances in powders have been deduced, calculating the relative intensities around the resonance frequencies. The shape of the resonance curve to be recorded can be found by the difference between the unperturbed and perturbed lines. When the asymmetry parameter η has a finite value, the recorded peak shifts from the unperturbed position. This effect is more evident for the weaker modulation field or the broader unperturbed line, and also for larger values of η. Furthermore, it is shown that the higher resonance line is much stronger than the lower, when η is large.