Low temperature Raman spectra of KHCO3 single crystal

The KHCO3 single crystal Raman spectra at 300K and 30K have been investigated in the 4000–5 cm−1 range. The far infrared spectrum (300–60 cm−1) of polycrystalline KHCO3 has also been obtained. Fifteen Raman and five infrared active lattice modes from respectively eighteen and fifteen expected ones have been observed. An assignment in terms of factor group symmetry species, rotational, translational and hydrogen bond vibrations is given. Hydrogen bond strength, OH stretching band shape and structure are discussed; combination bands involving mostly OH bending fundamentals are believed to be responsible for the main subband features.