Strontium tetra­fluoridoborate and barium tetra­fluoridoborate

In Sr(BF₄)₂, which is isomorphous with the previously published Ca(BF₄)₂, the metal atom is eight-coordinated with a square-anti­prismatic environment. Each tetra­fluorido­borate anion is bonded to four metal centers. In the barium derivative, the metal center, with symmetry 2/m, is surrounded by 14 F atoms. The B atom and two of the three independent F atoms occupy special positions with symmetry m. Each anion is connected to five Ba atoms.