Crystal structure of the monoclinic modification of KNd(SO4)2

A hydrothermal method was used to prepare the monoclinic modification of KNd(SO4)2 with space group P21/c, a = 8,551(1), b = 7.159(1), c = 10.679(1) angstrom, β = 92.42(1)degree, Z = 4. The data were obtained on a CAD-4 automatic diffractometer using the anisotropic method of least squares for 1747 reflections to give R = 0.037 and Rw = 0.052. A laminar structural pattern was found. A comparative crystal chemical analysis was carried out for KNd(SO4)2, MTR(EO4)2·nH2O (E = S, Se, n = 0, 1, 2), datolite, herderite, and gadolinite