Voigt profile is also used in the case of the spin resonance lines. In solids, these lines "are broadened by a number of mechanisms" . "Some of these mechanisms give a Gaussian lineshape, such as dipolar broadening in concentrated crystals and strain broadening by dislocations . Other mechanisms lead to a Lorentzian lineshape, such as the relaxation broadening due to the finite lifetime of a state" , is referring to the analogous broadening mechanism that we find in ). According to Stoneham, "If the mechanisms which lead to Lorentzian and Gaussian broadening are independent, the lineshape is just the convolution of a Gaussian and a Lorentzian". That is, a Voigt function.