Fig. 1: Dynamic structure factor and vibrational spectra for solid and liquid ammonia.

a, b Integrated dynamic structure factor S(Q,E) measured with SEQUOIA spectrometer for incident energies of 30 and 70 meV at various temperatures for ND3 (c) Integrated S(Q,E) measured with VISION spectrometer for NH3 (the spectra are vertically shifted for clarity). d–f Full S(Q,E) spectra measured for ND3 with incident energy 30 meV with increasing temperature from left to right plotted with same intensity scale. g–i Full S(Q,E) measured for ND3 with incident energy 70 meV with increasing temperature from left to right plotted with same intensity scale.