Alternative form for the pseudo-Voigt peak shape

A number of different approximations are in use in different fields of spectroscopy for calculating the Voigt line shape. The most popular among them is the pseudo-Voigt line shape. Its main disadvantage is that it is quite complicated to conclude from its parameters the natural width of the line and the spectrometer contribution. Furthermore there exists no simple possibility to replace the line shape with a more accurate approximation to the Voigt shape. An alternative form for this peak shape is presented, which is parametrized with the natural width and spectrometer contribution and transparently maps these parameters to the parameters “Gauss/Lorentz mixing ratio” and “total width.” This representation keeps the calculation simple and quick. Furthermore it allows a smooth transition to the more accurate Voigt approximations.