Crystallography of the CaGa2O4 polymorphs

Single crystals of the three polymorphs of CaGa 2 O 4 reported by Jeevaratnam and Glasser 1 have been studied. CaGa 2 O 4 -I is orthorhombic, with a = 7.73, b = 9.14, c = 10.36 Å; CaGa 2 O 4 -II is orthorhombic with a = 5.32, b = 14.38, c = 16.82 Å; m -CaGa 2 O 4 is monoclinic with a = 7.86, b = 8.90, c = 10.55 Å, β = 93°. These cell dimensions do not resemble any of those previously reported for other RO · R 2 O 3 compounds.