Dipotassium hydrogencarbonate fluoride monohydrate

Single crystals of the title compound, K₂(HCO₃)F·H₂O, were obtained as a secondary product after performing flux synthesis experiments aimed at the preparation of potassium rare earth silicates. The basic building unit of the structure is an [(HCO₃)(H₂O)F]²⁻ zigzag chain running parallel to [001]. Both types of anions as well as the water mol­ecules reside on mirror planes perpendicular to [010] at y = 0.25 and y = 0.75, respectively. Linkage between the different constituents of the chains is provided by O—H...O and O—H...F hydrogen bonding. The K⁺ cations are located between the chains and are coordinated by two F and five O atoms in form of a distorted monocapped trigonal prism.