Practical Electron Microscopy and Database

A Lorentzian function is a single-peaked function that decays gradually on each side of the peak. Lorentzian distribution is given by,

           ------------------------- [2511]
where,
          H -- The full width at half maximum (FWHM),
          C_L -- = 4,
          C_L^1/2/πH -- The normalization factor for the Lorentzian function such that .

The general forms of Lorentzian and Gaussian distributions are shown in Figure 2511. The Lorentzian distribution has a much smaller degree of tailing than Gaussian distribution.

Figure 2511. General forms of Lorentzian and Gaussian distributions.