Refinement of the crystal structure of zinckenite, Pb6Sb14S27

Abstract

Several modifications of TlInS2 crystallize from melts of this composition with annealing at various temperature. Symmetries and lattice parametors determined by the x-ray precession method are as follows: I . { = ß), monociinic, o ~ 6 = 7.76 ± O.Ol Ä, c = 30.01 ± 0.02 Ä, ^ = 9 0 ° 1 0 ' ± 5 ' , P2 i /m, Z = 16, Dx = 5.64 g/cm». I I . monociinic, a = 7.77 ± O.Ol Ä, 6 = 7.74 ± O.Ol Ä, c = 240 ± 1 Ä, ß = 90° 15' ± 5', P2 i /m, Z = 128, D^ = 5.64 g/cm^. I I I . triclinic, a = 7.70 ± O.Ol Ä, 6 = 7.77 ± O.Ol Ä, c = 122 ± 1 Ä, a = 90°11' ±5', ß = 90°26' ± 5', y = 90°6' ± 5', P I , Z = 64, D^ = 5.59 g/cm3. IV. ( = a), hexagonal, a = 7.67 ± 0.05 Ä, c = 14.98 ± 0.05 Ä, P6/mcc or P6cc , Z = 8, Dx = 6.73g/cm3. The crystal symmetry of the polymorphs of TlInS2 105