The crystal structure of trechmannite, AgAsS2*
Abstract
The crystal structure of trechmannite, AgAsS2, has been determined with the use of three-dimensional intensity data. The crystal is rhombohedral, having the unit-cell dimensions arh = 8.62 Å, αrh = 108°17′, ahex = 13.98 Å, chex = 9.12 Å, space group C3i2−R[unk]. There are 6 (rh.) or 18 (hex.) formula units in the cell. The structure was solved by interpretation of a three-dimensional partial Patterson function synthesized only with superlattice reflections and by the heavy-atom method.
The crystal has a defect, distorted, galena-type structure, the metal atom positions and the S-atom positions on the threefold rotation axes being vacant. Six S atoms and six As atoms surround the vacant sites for metal and for S respectively.
As has three nearest S neighbours at distances between 2,218 Å and 2.307 Å, which form the usual trigonal AsS3 pyramid. Three of these AsS3 pyramids form a threefold AS3S6 ring by sharing S atoms. This result could be expected for stereochemical reasons. If the ratio As:S is 1:2, the only possibilities are infinite chains of linked AsS3 pyramids or rings, with a threefold axis a threefold As3S6 ring is probable.
Ag has three nearest S neighbours between 2.599 Å and 2.646 Å, with which it forms a very flat pyramid. A fourth S atom is at an intermediate distance of 2.735 Å. Together these four S atoms form a distorted tetrahedral coordination around the Ag atoms.
Artikel in diesem Heft
- Zur Absorption der Ewaldwellen; Messungen bei simultaner Reflexion an (111) und ([unk]11) des Germaniums
- Die Verteilung der Valenzelektronen im Mg2Si
- Redetermination of the crystal structure of α-d-glucosamine hydrohalides*
- Crystal structure of d-leucyl glycine hydrobromide*
- The crystal structure of orthoenstatite
- The crystal and molecular structure of l-ornithine hydrochloride
- Untersuchungen über Umweganregung und ihre Vermeidung am Beispiel des Na2BeF4*
- Analysis of density distribution of the outer electrons in hexamine*
- Bestimmung des Elastizitätstensors trikliner Kristalle: Beispiel CuSO4 · 5H2O
- The crystal structure of 2-aminoethyl seleninic acid · HCl, NH2CH2CH2SeOOH · HCl
- Strukturuntersuchung an Bariumazid Ba(N3)2
- Energetics of conducting halides
- The crystal structure of trechmannite, AgAsS2*
- Die Kristallstruktur von Baumhauerit*
- The crystal structure of rubidium hydrogen fumarate, RbC4H3O4
- Die Kristallstruktur von Imidazol, C3N2H4, bei Zimmertemperatur
- Verfeinerung der Kristallstruktur von Benitoit BaTi[Si3O9]
- The crystal structure of In5Bi3
- Über den Ersatz von Li1+ durch Cu1+ in oxidischen Spinellen*
- Cu1+-haltige Doppeloxide mit seltenen Erdmetallen1
- Transformations ordre-désordre de la cordiérite
- The crystal structure and chemical composition of pollucite
- Die optische Orientierung der Plagioklase
- World Directory of Crystallographers
Artikel in diesem Heft
- Zur Absorption der Ewaldwellen; Messungen bei simultaner Reflexion an (111) und ([unk]11) des Germaniums
- Die Verteilung der Valenzelektronen im Mg2Si
- Redetermination of the crystal structure of α-d-glucosamine hydrohalides*
- Crystal structure of d-leucyl glycine hydrobromide*
- The crystal structure of orthoenstatite
- The crystal and molecular structure of l-ornithine hydrochloride
- Untersuchungen über Umweganregung und ihre Vermeidung am Beispiel des Na2BeF4*
- Analysis of density distribution of the outer electrons in hexamine*
- Bestimmung des Elastizitätstensors trikliner Kristalle: Beispiel CuSO4 · 5H2O
- The crystal structure of 2-aminoethyl seleninic acid · HCl, NH2CH2CH2SeOOH · HCl
- Strukturuntersuchung an Bariumazid Ba(N3)2
- Energetics of conducting halides
- The crystal structure of trechmannite, AgAsS2*
- Die Kristallstruktur von Baumhauerit*
- The crystal structure of rubidium hydrogen fumarate, RbC4H3O4
- Die Kristallstruktur von Imidazol, C3N2H4, bei Zimmertemperatur
- Verfeinerung der Kristallstruktur von Benitoit BaTi[Si3O9]
- The crystal structure of In5Bi3
- Über den Ersatz von Li1+ durch Cu1+ in oxidischen Spinellen*
- Cu1+-haltige Doppeloxide mit seltenen Erdmetallen1
- Transformations ordre-désordre de la cordiérite
- The crystal structure and chemical composition of pollucite
- Die optische Orientierung der Plagioklase
- World Directory of Crystallographers
