Single‐crystal X ray study of γ Mg2SiO4

The crystal structure of the spinel polymorph of Mg2SiO4 has been refined using a single crystal synthesized at 220 kbar and 1000°C. The u parameter of the structure with a = 8.0649(1) Å is 0.3685(6). Although the refinement indicates some cation disorder in Mg2SiO4 spinel, the results are not definitive because of the similarity in the scattering factors of Mg and Si. The average Si‐O and Mg‐O distances are 1.655(4) and 2.070(4) Å, respectively. The final R and Rw values are 0.048 and 0.040 for 41 reflections up to sin θ/λ = 1.0.