1982 Volume 77 Issue 9 Pages 305-309
The crystal structure of NaTiSi2O6 pyroxene synthesized at 1500°C and 50 kb has been refined by the least squares method using 763 reflections measured using an automatic single crystal diffractometer. The unweighted R factor is 0.041 for 687 unrejected reflections. The cell dimensions are; a 9.692 Å, b 8.874 Å, c 5.301 Å, β 106.85°, and V 436.37 Å3; space group C2/c.
Comparison of a new crystal structure refinement for the NaTiSi2O6 pyroxene with published refinements for six NaM3+Si2O6 pyroxene indicates that the Si-O distances correlate with the electronegativity of the M3+ ion as two separate trends. Ore is Sc-V-Ti-Al series and the other is Cr-In-Fe series.