Abstract
The crystal structure of LiScSiO4 olivine (Pbnm; a = 4.8214(7), b = 10.444(1), c = 5.9729(9) Å) has been determined and refined with anisotropic thermal parameters to an unweighted disagreement factor of 0.016. Lithium occupies the M1 site and Sc the M2 site. A comparison with isotopic MggSiO4 allows recognition of structure modifications due primarily to a change of the formal charge on the octahedral cations. Important features are (1) large changes in tetrahedral geometry due to interaction of Sc3+ and Si across a shared adge; (2) uniform increase in Li—O distances compared to Mg—O distances in the M1 site due to larger Li1+; (3) both increases and decreases of bond distances of the M2 octahedron relative to those in Mg2SiO4.