Characterization of the C = O stretching and NH₂ scissoring bands of NH₂CHO. Top: the C = O stretching and NH₂ scissoring bands of NH₂CHO in pure and mixed forms at selected temperatures. Bottom left: the peak position and FWHM of the formamide C = O stretch in pure and mixed forms at selected temperatures. Bottom right: the band strengths of the formamide C = O stretch and NH₂ scissor in mixtures relative to the pure band strength (all at 15 K).