The crystal structure of LiAlSi2O6-II (“β spodumene”)
Abstract
LiAlSi2O6-II (“β spodumene”) was found to be tetragonal, space group P43212 (or P41212), a = 7.541 ± 0.001, c = 9.156 ± 0.002 Å, Z = 4, Do = 2.365 and Dc = 2.374 g/cm3. The bond lengths were determined with an accuracy of 0.006 Å for (Si,Al)–O bonds and 0.041 Å for Li–O bonds. The final R value was 6.2%. The structure consists of a three-dimensional aluminosilicate framework. The framework was confirmed to be isotypic with keatite. The Li atoms were found to be coordinated to four oxygen atoms. The distribution of Si and Al in the tetrahedra is random. The structure is dominated by interlocking 5-membered rings of (Si,Al) tetrahedra. All the five-membered rings run approximately parallel to either (010) or (100), and thus help to create zeolite-like channels. These channels account for the ion-exchange properties of LiAlSi2O6-II. Lithium atoms are stuffed in interstitial positions but occupy a general eight-fold site. The four lithium atoms per unit cell are distributed among four sets of paired sites of the eight-fold positions. An explanation for the unusually low thermal expansion behavior of LiAlSi2O6-II is given.
Articles in the same Issue
- A special case of two-dimensionally disordered crystals
- Die Kristallstruktur des Koenenits, eine Doppelschichtstruktur mit zwei inkommensurablen Teilgittern
- Zur Indizierung von Pulverdiagrammen tetragonaler und hexagonaler Substanzen
- Etch patterns on apophyllite basal cleavages
- Die Kristallstruktur von Li2(Si0,25Ge0,75)2O5
- The crystal structure of LiAlSi2O6-II (“β spodumene”)
- Phase solution of para-chlorophenol
- Crystal structure of an eighteen-layered polytype of cadmium iodide
- X-ray diffraction effects by non-ideal crystals of biotite, muscovite, montmorillonite, mixed-layer clays, graphite, and periclase*
- The crystal structure of alamosite, PbSiO31
- Sauerstoff als Koordinationszentrum in Kristallstrukturen
- Low-iron polymorphs in the pyrrhotite group
- Revised crystal structure of dehydrated Na-Type A zeolite
- Verfeinerung der Tl2O3-Struktur mittels Neutronenbeugung
- The location of hydrogen atoms in crystalline ionic hydrates
- Disorder phenomenon in cadmium iodide crystals
- Crystal structure of single-layer lizardite
- Proof that the pgg packing of ellipses has never the maximum density
- Weighting function in crystal-structure analysis*
- Tetrahedral metal groups in Fe2B and Mn4B structures
- Antisymmetrische OD-Strukturen
- Studies on etching of neutron-irradiated calcium fluoride single crystals
- Matrix methods in Fourier summations
- Electron-optical studies of etch patterns on calcium fluoride
- Structure of etch pattern at helical dislocations in NaCl single crystals
- Crystal structure of l(+)-cysteine hydrochloride monohydrate*
- Eighth International Congress of Crystallography
- Intercongress Meeting, 1968
Articles in the same Issue
- A special case of two-dimensionally disordered crystals
- Die Kristallstruktur des Koenenits, eine Doppelschichtstruktur mit zwei inkommensurablen Teilgittern
- Zur Indizierung von Pulverdiagrammen tetragonaler und hexagonaler Substanzen
- Etch patterns on apophyllite basal cleavages
- Die Kristallstruktur von Li2(Si0,25Ge0,75)2O5
- The crystal structure of LiAlSi2O6-II (“β spodumene”)
- Phase solution of para-chlorophenol
- Crystal structure of an eighteen-layered polytype of cadmium iodide
- X-ray diffraction effects by non-ideal crystals of biotite, muscovite, montmorillonite, mixed-layer clays, graphite, and periclase*
- The crystal structure of alamosite, PbSiO31
- Sauerstoff als Koordinationszentrum in Kristallstrukturen
- Low-iron polymorphs in the pyrrhotite group
- Revised crystal structure of dehydrated Na-Type A zeolite
- Verfeinerung der Tl2O3-Struktur mittels Neutronenbeugung
- The location of hydrogen atoms in crystalline ionic hydrates
- Disorder phenomenon in cadmium iodide crystals
- Crystal structure of single-layer lizardite
- Proof that the pgg packing of ellipses has never the maximum density
- Weighting function in crystal-structure analysis*
- Tetrahedral metal groups in Fe2B and Mn4B structures
- Antisymmetrische OD-Strukturen
- Studies on etching of neutron-irradiated calcium fluoride single crystals
- Matrix methods in Fourier summations
- Electron-optical studies of etch patterns on calcium fluoride
- Structure of etch pattern at helical dislocations in NaCl single crystals
- Crystal structure of l(+)-cysteine hydrochloride monohydrate*
- Eighth International Congress of Crystallography
- Intercongress Meeting, 1968
