the water that combines with salts when they crystallize, water molecules forming an essential part of the crystal structure of some compounds, water present in the crystals of certain compounds. It is chemically combined in stoichiometric amounts, usually by coordinate or hydrogen bonds, but can often be easily expelled., kristallide koostisse kuuluv vesi; märgitakse aine valemis; tuntud kristallveega soolad on näiteks vitriolid