Die Kristallstruktur von Na4CaSi3O9 und dessen strukturelle Beziehungen zu K4SrGe3O9 und Ca3Al2O6

Abstract

Abstract Na4CaSi3O9 crystallizes in space group Pa3 with a = 15.087(2) Å and Z = 16 formula units per unit cell. The refinement of the atomic parameters gave a final R-value of R = 0.063 (Rw = 0.054) for 1227 observed reflections. The compound is isostructural with K4SrGe3O9, the crystal structure contains rings of 12 corner-sharing SiO4 tetrahedra normal to the three-fold axes. A close structural relationship also exists to tricalciumaluminate Ca3Al2O6 which contains Al6O18-rings of corner-sharing A1O4 tetrahedra.