Crystal structure, large distortion of the Zn tetrahedron, and statistical displacement of water molecules in skorpionite

The crystal structures of skorpionite from the Skorpion zinc deposit in Namibia [Ca3Zn2(PO4)2CO3(OH)2·H2O; monoclinic; a = 19.0715(8), b = 9.3321(3), c = 6.5338(3) Å, β = 92.6773(12)°; space group C2/c] and [a = 19.0570(14), b = 9.3346(5), c = 6.5322(4) Å, β = 92.752(2)°; space group Cc] are analyzed using single–crystal X–ray diffraction and refined to yield R values of 0.0253 and 0.0272 for 1576 and 2446 unique reflections with Fo > 4σ(Fo),...