Accurate numerical approximation to the Gauss-Lorentz lineshape

The Gauss-Lorentz lineshape often observed in EPR or NMR is shown to be simply related to the complex error function. Using numerical algorithms developed for the evaluation of this function, experimental lineshapes can be accurately and rapidly simulated. Formulas are presented for the derivatives of the line profile with respect to the parameters and for the approximate computation of the overall linewidth. It is observed that accurate integrals require use of a wide integration interval. (C) 1997 Academic Press.