The crystal structure of Görgeyite K2SO4 · 5 CaSO4 H2O
Abstract
The crystal structure of the mineral görgeyite, K2SO4 · 5 CaSO4 · H2O, has been determined from visually estimated photographic intensities using the direct methods program MULTAN, and refined by block-diagonal least-squares structure factors to an R value of 0.096. The mineral is monoclinic and contains four formula units in a cell of dimensions a= 17.51(1), b = 6.822(5), c= 18.21(1) Å, β = 113.3° and space group C2/c.
Two independent calcium atoms, one of which sits on the diad axis, are nine-fold coordinated by oxygen atoms in a closely similar arrangement, with average Ca–O distances of 2.52 Å in the range 2.40–2.68 Å. A third calcium atom is eight-fold coordinated with a mean Ca–O distance of 2.46 Å in a range of 2.37–2.64 Å.
The potassium atom is also eight-fold coordinated. The three independent sulphate ions are approximately regular with mean S–O distances of 1.472(8), 1.477(27), and 1.470(7) Å respectively but their behaviour in providing oxygen coordination is different for each. The hydrogen atom of the water molecule has not been positively located though it is likely that a hydrogen bond is present.
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- Fritz Laves 27.2.1906–12.8.1978
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- The crystal structure of Görgeyite K2SO4 · 5 CaSO4 H2O
- An X-ray diffraction study of barium thiosulphate monohydrate, BaS2O3 · H2O
- Tourmaline as a pyroelectric infra-red radiation detector
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- X-ray topographic and ferroelastic studies of 2MC-Sb5O7J single crystals
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- Darstellung und Kristallstruktur der ternären Boride SrNi12B6 und BaNi12B6
- The crystal structure of chalcophyllite
- Powder diffraction studies on aluminite and meta-aluminite
- Back-reflection precession camera, a new instrument in reciprocal-lattice photography
- A preliminary report on the structure of ZnMn3O7
- Crystal data for 2-(p-bromophenyl)-trans-5,6pentamethyl-2,3,4,6-tetrahydro-l,3-oxazin-4 on C15H18BrNO2 and 2-(p-bromophenyl)trans-4a,5,6,7,8,8a-hexahydrochinazolin-4(3H) on C14H15BrN2O
- The crystal structure of Ba2Ni9B6
- Redetermination of the structure of anhydrous zinc metaborate Zn4O(BO2)6
Articles in the same Issue
- Fritz Laves 27.2.1906–12.8.1978
- Similarity and miscibility of inorganic crystals*
- Symmetry of reflexion intensity 10.L. and its connection with the notation of layer sequence of Cdl2 polytypes for a structure analysis application
- The crystal structure of Görgeyite K2SO4 · 5 CaSO4 H2O
- An X-ray diffraction study of barium thiosulphate monohydrate, BaS2O3 · H2O
- Tourmaline as a pyroelectric infra-red radiation detector
- Die Bestimmung der Al/Si-Verteilung mittels Neutronenbeugung in einem Plagioklas An66
- Crystal structure of sapphirine-lTc
- X-ray topographic and ferroelastic studies of 2MC-Sb5O7J single crystals
- Die Kristallstrukturen von Li3Ni20B6 und Li~3Ni16B~8
- Darstellung und Kristallstruktur der ternären Boride SrNi12B6 und BaNi12B6
- The crystal structure of chalcophyllite
- Powder diffraction studies on aluminite and meta-aluminite
- Back-reflection precession camera, a new instrument in reciprocal-lattice photography
- A preliminary report on the structure of ZnMn3O7
- Crystal data for 2-(p-bromophenyl)-trans-5,6pentamethyl-2,3,4,6-tetrahydro-l,3-oxazin-4 on C15H18BrNO2 and 2-(p-bromophenyl)trans-4a,5,6,7,8,8a-hexahydrochinazolin-4(3H) on C14H15BrN2O
- The crystal structure of Ba2Ni9B6
- Redetermination of the structure of anhydrous zinc metaborate Zn4O(BO2)6
