Preliminary analysis of the X-ray diffraction of single crystals provides the unit cell parameters and suggests standard B-type packing of the polymethylene chains. Spectral hole burning of the N-D stretching bands of ammonium stearate, doped with some deuterium, produces holes and antiholes in three regions of the spectrum. The three regions contain the stretching bands, the NH3 rocking bands, and the rocking-libration bands, respectively. The holes and antiholes identify the vibrational bands and correlate them with the different possible orientations of the NH3D+ in the crystal.