Results from die scattering of nearly monoenergetic (DELTAE/E almost-equal-to 2%) thermal energy He atoms from the LiF(001) surface are presented and discussed with particular emphasis on multiphonon interactions. These experiments represent the next step in a series of experiments exploring the multiphonon scattering of He from alkali halides in that previous work [G. G. Bishop et al., Phys. Rev. B 47, 3966 (1993)] has now been extended to include nonspecular angles. The LiF surface was prepared as in the previous experiments by cleaving the crystal in air and cleaning it by sublimation in the ultrahigh vacuum system. The measurements consist of time-of-flight spectra of the scattered He atoms taken for a number of incident angles as a function of the surface temperature ranging from 290 to 720 K and for He incident wave vectors ranging from 7 to 11 angstrom-1. Analysis of the data was carried out using a theoretical model developed by Manson [Phys. Rev. B 43, 6924 (1991)], which allows the determination of the interaction potential between the incident atoms and the LiF surface by isolating die scattering form factor. The good representation of die multiphonon scattering found from die model allows this background to be subtracted from the time-of-flight spectra to enhance the single-phonon He atom scattering signal, which in turn permits improved surface phonon dispersion measurements and interpretation.