Line broadening effects in nuclear quadrupole resonance

The major broadening mechanism in Nuclear Quadrupole Resonance is the spread in the electric field gradient produced by crystal defects. In multilevel spin systems, the frequencies of the various possible resonances are different functions of the components of the electric field gradient. This paper examines the role of both the principal component of the field gradient and the asymmetry component in the relationship between the linewidths of the two resonances of I = $\text{5}\text{2}$ nuclei. Comparison with experimental data shows various ways in which defects interact with quadrupolar nuclei.