[en] Moessbauer diffraction experiments have been performed on a LiNbO₃ single crystal at room temperature for scattering angles between 14.5 and 40.5⁰. A large contribution of inelastically scattered intensity was detectable for all scattering angles. Radiation damage caused by the high-energy components of the radiation emitted by the ⁵⁷Co Moessbauer source was observed. An attempt was made to estimate the temperature factor B from the measured inelastically scattered radiation assuming that first order thermal diffuse scattering (TDS) is dominant. Both the TDS contribution to the integrated intensity within the Bragg peak and the ratio of the integrated first-order TDS included in the Bragg peak to that included in the background were calculated with various programs from the elastic constants and compared with the experimental values. (Auth.)