The application of the partial Patterson method and the thirteenfold hexagonal superstructure of Cu7As6Se13
Abstract
Derivative structures based upon sphalerite or galena often exhibit hexagonal superstructures characteristic of a peculiar thirteenfold multiplicity. A synthetic semiconductor, Cu7As6Se13, is one of the examples. Crystals of Cu7As6Se13 are rhombohedral with a = 8.71 Å, α = 105°41′. The space group is R3. The unit cell referred to hexagonal axes has dimensions a = 14.025 Å, c = 9.61 Å, and there are three formula units per cell. As an example of the application of the partial Patterson method, the superstructure was solved based upon a three-dimensional Patterson function synthesized with superstructure reflections alone.
The structure is a distortion structure based upon sphalerite. The maximum distortion from sphalerite is around 0.2 Å. In terms of the theory of derivative crystal structures, it has been shown that the thirteenfold superstructures are smallest probable ones for rhombohedral distortion structures based upon sphalerite or galena.
Articles in the same Issue
- Some conditional distributions of the structure factors and related conditional expectation values
- γ Na2BeF4, its crystal structure at 25° and 74°C and its anisotropic thermal expansion
- Crystal structure and hydrogen bonding of copiapite
- The crystal and molecular structure of 4,8,9,10-tetrachloro-2,6-dithiaadamantane, C8H8Cl4S2*
- Wirkungsbereichstypen einer verzerrten Diamantkonfiguration mit Kugelpackungscharakter
- The application of the partial Patterson method and the thirteenfold hexagonal superstructure of Cu7As6Se13
- The investigation of superstructures by means of partial Patterson functions
- Die Kristallstruktur von Strontiumnitrat-Tetrahydrat, Sr(NO3)2 · 4H2O
- Bemerkungen zur Geschichte der Raumgruppen-Symbole von Fedorow, Schoenflies und Hermann-Mauguin*
- Structure refinement of anthrone, C14H10O
Articles in the same Issue
- Some conditional distributions of the structure factors and related conditional expectation values
- γ Na2BeF4, its crystal structure at 25° and 74°C and its anisotropic thermal expansion
- Crystal structure and hydrogen bonding of copiapite
- The crystal and molecular structure of 4,8,9,10-tetrachloro-2,6-dithiaadamantane, C8H8Cl4S2*
- Wirkungsbereichstypen einer verzerrten Diamantkonfiguration mit Kugelpackungscharakter
- The application of the partial Patterson method and the thirteenfold hexagonal superstructure of Cu7As6Se13
- The investigation of superstructures by means of partial Patterson functions
- Die Kristallstruktur von Strontiumnitrat-Tetrahydrat, Sr(NO3)2 · 4H2O
- Bemerkungen zur Geschichte der Raumgruppen-Symbole von Fedorow, Schoenflies und Hermann-Mauguin*
- Structure refinement of anthrone, C14H10O
