42
1 A Historical Review of the Structures of Water and Ice
Fig. 1.30 Elements of the
dynamic structure of water.
Numbers depict: (1) proton
transport, (2) molecular
adjustment, (3) interstitial
diffusion, and (4)
molecular/ionic vibrations,
respectively
1
2
3
4
most of which recombine in 0.1 ps, but some of them can live significantly longer.
The migration of the excess charge passes through the interconversion of Eigen and
Zundel cations.
Despite the fact that the individual properties of water and ice are well described
by variations of the Bernal–Fowler model, none of the existing models is capable
of explaining a sufficient set of properties necessary for a final description of the
dynamical structure. Dielectric relaxation, DC conductivity, the dielectric constant,
and infrared absorption are explained separately, but using specific models. Table 1.5
shows several common misconceptions related to the structure of water, which originate from the imperfection of the Bernal–Fowler approach. These misconceptions
contradict modern experimental data but are still used in some water models.
Recently, several experimental results were obtained which showed that the
Bernal–Fowler model of water fails to reproduce the properties of water, at short
(picosecond) time intervals, and also those for water at nanoscales. These results
change our current understanding of water’s structure and dynamics, and require
a significant reconsideration of our vision of water. There are several remarkable
examples of the anomalous properties of water, which show that specific details of
the water structure and its dynamics are still far from completely understood.
The spatial heterogeneity of water. Small-angle X-ray scattering (SAXS) demonstrates the presence of density fluctuations in ambient water on a physical length
scale of about 1 nm [127]. The independent measurements of the time-resolved optical Kerr effect shows characteristic features near 50 and 200 cm
−1 , which indicate
the coexistence of two local structures with high density and low density [16]. This
effect is explained in Sect. 4.4 (see Fig. 4.6) within the ionic model of water.
The time heterogeneity of water. A femtosecond pump–probe spectroscopy study
of the OH-stretching mode of HDO dissolved in D 2 O shows that the orientational
relaxation of the HDO molecules occurs in either 13 ps or 0.7 ps, which suggests
that two distinct molecular species exist in liquid water with respect to orientational
dynamics [128]. A parallel analysis of DC and terahertz conductivity of water reveals
two time intervals, which correspond to different interaction potentials, thus exhibit-
1 A Historical Review of the Structures of Water and Ice
Fig. 1.30 Elements of the
dynamic structure of water.
Numbers depict: (1) proton
transport, (2) molecular
adjustment, (3) interstitial
diffusion, and (4)
molecular/ionic vibrations,
respectively
1
2
3
4
most of which recombine in 0.1 ps, but some of them can live significantly longer.
The migration of the excess charge passes through the interconversion of Eigen and
Zundel cations.
Despite the fact that the individual properties of water and ice are well described
by variations of the Bernal–Fowler model, none of the existing models is capable
of explaining a sufficient set of properties necessary for a final description of the
dynamical structure. Dielectric relaxation, DC conductivity, the dielectric constant,
and infrared absorption are explained separately, but using specific models. Table 1.5
shows several common misconceptions related to the structure of water, which originate from the imperfection of the Bernal–Fowler approach. These misconceptions
contradict modern experimental data but are still used in some water models.
Recently, several experimental results were obtained which showed that the
Bernal–Fowler model of water fails to reproduce the properties of water, at short
(picosecond) time intervals, and also those for water at nanoscales. These results
change our current understanding of water’s structure and dynamics, and require
a significant reconsideration of our vision of water. There are several remarkable
examples of the anomalous properties of water, which show that specific details of
the water structure and its dynamics are still far from completely understood.
The spatial heterogeneity of water. Small-angle X-ray scattering (SAXS) demonstrates the presence of density fluctuations in ambient water on a physical length
scale of about 1 nm [127]. The independent measurements of the time-resolved optical Kerr effect shows characteristic features near 50 and 200 cm
−1 , which indicate
the coexistence of two local structures with high density and low density [16]. This
effect is explained in Sect. 4.4 (see Fig. 4.6) within the ionic model of water.
The time heterogeneity of water. A femtosecond pump–probe spectroscopy study
of the OH-stretching mode of HDO dissolved in D 2 O shows that the orientational
relaxation of the HDO molecules occurs in either 13 ps or 0.7 ps, which suggests
that two distinct molecular species exist in liquid water with respect to orientational
dynamics [128]. A parallel analysis of DC and terahertz conductivity of water reveals
two time intervals, which correspond to different interaction potentials, thus exhibit-