Structured water products claim to contain clusters of water molecules that are especially beneficial to human health. Producing many of the structures of water molecules in these products is not only chemically impossible, there is no evidence that any particular arrangement of water molecules is beneficial or harmful to health.
Many products claiming to contain structured water state that organisms prefer water in certain crystal arrangements. Some of these products use the hexagonal or fractal structure of snow water as evidence of natural structured water. A rudimentary understanding of chemistry shows that snow water assumes regular crystal structures not because this is the water's ideal state, but because the water is frozen.
Many companies offer products that claim to structure water for the user, providing them with health benefits. Of course, the only way to make water assume a regular crystal shape is to freeze it. Liquid water molecules always assume a random, isotropic structure. Isotropic means that the water solution is equally random in all directions.
Structured water is unrelated to the genuine scientific phenomenon of water clusters. Water clusters are large, mostly regular arrangements of liquid water molecules that form and dissociate extremely quickly. Water clusters form and dissociate at rates of about once every 200 quadrillionths of a second. Scientists do not understand why or how water clusters form, nor are they able to recreate them in the laboratory.