Far-infrared reflectivity spectra of L-arginine phosphate monohydrate (LAP)

Abstract Far-infrared (IR) reflectivity spectra of L-arginine phosphate monohydrate (LAP) are measured for the first time, for both polarizations parallel and perpendicular to the twofold b-axis, between 7 and 250 K, in the frequency range 10–600 cm −1 . The phonon modes are classified within their symmetry species, and their frequencies and oscillator strength are calculated from the analysis of the experimental spectra. The present study confirms the absence from a structural phase transition below room temperature.