"Raman scattering from liquid H2O consists of the O-H stretching vibration band (2800 3400 cm -1 ), the v2 bending band near 1645 cm -1 , the combination of bending and libration bands (v2+vL) near 2100 cm -1 , and intermolecular fluctuation bands in the low-frequency regions which are due to the interaction between water molecules through the hydrogen bonds" . For what is regarding the low frequency region, Faurskov , is mentioning that "Raman spectroscopy is a very fast technique, so the water molecules can be considered to be in specific sites during the time it takes to obtain a Raman spectrum. It means that in this Raman picture, we can talk about a fixed water structure", that is, "a hydrogen-bonded network with a continuous breaking and making of hydrogen bonds". Faurskov Nielsen is also mentioning the works by Walrafen, where we can find the water "five-mer". "It means a water molecule forming hydrogen bonds to four other molecules." .