Crystal structure of sodium tetratungstate, Na2W4O13

Abstract

The structure of Na₂W₄O₁₃ has been determined by Patterson and Fourier methods from 426 independent reflections measured photographically. The basic units, consisting of four edge-shared octahedra, are linked along two crystallographic directions by corner sharing to form octahedral layers, which are held together by sodium atoms. The W–O linkage is similar to that in K₂Mo₄O₁₃, but is new for tungstates. Crystals are triclinic, space group P, with Z= 1, in a unit cell of dimensions: a= 11·163(5), b= 3·894(1), c= 8·255(3)Å, α= 90·60(2), β= 131·36(2), γ= 79·70(2)°. The structure was refined by least squares to R 0·117.