Gas electron diffraction (GED) data for SeF6 were recorded with the University of Arkansas real-time diffractometer in the temperature range 298-573 K. The effects of higher-order cumulants, of multiple scattering, and of an assumed asymmetry Morse-like constant on the results of the analysis were investigated. The study illustrates that temperature-dependent molecular GED intensities can be useful in assigning high-resolution vibration-rotation spectra of molecules containing heavy central atoms and in testing the accuracy of molecular force fields obtained from spectroscopy. Applying the cumulant method for analyzing GED data, r(e)(Se-F) = 167.84 (8) pm was obtained.