Inter- and intra-molecular OH stretching modes of bicarbonate in aqueous solution

The ambiguous assignments of the CO-H stretching (ν1) mode of bicarbonate ion in Raman and IR spectra were clarified based on a careful investigation of hydrogen bonding and its influence on the power spectra evaluated from the velocity autocorrelation functions obtained by an ab initio QMCF MD simulation. The ν1 spectrum includes inter- and intra-molecular OH stretching modes of hydrated bicarbonate ion and is presented together with the other vibrations, namely the symmetric CO stretching (ν3), the C-OH stretching (ν5) and the CO3 out-of-plane deformation (ν8), modes.