Water free molecule, normal modes

Figure 10.4 Normal modes of vibration of the free water molecule.

A single water molecule has 3x3 = 9 normal modes. Six of them would have the angular frequencies co equal zero (they correspond to three free translations and three free rotations of the molecule in space). Three normal modes remain, and the vectors x of Eq. (7.11) for these... 

In addition to the three fundamental modes of the free water molecule, coordinated water exhibits other modes, such as those shown in Fig. 111-19. Nakagawa and Shimanouchi carried out normal coordinate analyses on [M(H20)6 - (T, symmetry) and(M(H20)4]- (D 4h symmetry) type ions to assign these low-frequency modes. Table 111-15 lists the frequencies and band assignments, and Fig. 111-23 illustrates the far-infrared. spectra of aquo complexes obtained by these authors. Adams and Lock also studied the infrared and... 

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