Ion-water structures

The formalism for X-ray diffraction is the same as that for neutron diffraction. However, because X-rays are scattered anisotropically by the electrons of the system, the form of the total radial distribution Gx(r) is a sum over the individual radial distribution functions convoluted by the X-ray form factor. It is therefore difficult to obtain detailed information regarding ion-water structure from a total G r), and recourse is usually made to models based on solid-state structures. Indeed, this procedure is at the heart of the comprehensive work of the Italian groups of Magini and Licheri 47). 

In general terms, the flexibility of the water network (and the relatively short relaxation times of the water molecules themselves) suggests that NDIS is an ideal probe of ion-water structures. Our observations demonstrate the uniqueness of each ion in terms of its own hydration zone. By extension, our results also strongly argue against the fundamental principle of homeopathy which suggests that by some fiction water molecules are able to remember the environments in which they have been sited. 

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