Mixed occupancy: the crystal structure of scheelite-type LiLu[MoO₄]₂

Area of Science:

• Inorganic Chemistry
• Solid-State Chemistry
• Crystallography

Background:

• Lithium and lutetium molybdates are of interest for various applications.
• Previous studies have investigated related compounds using powder X-ray diffraction.

Purpose of the Study:

• To synthesize and characterize lithium lutetium bis-[orthomolybdate(VI)], LiLu[MoO4]2.
• To determine the crystal structure of the title compound.
• To compare the findings with previous research.

Main Methods:

• Single crystal X-ray diffraction was employed.
• Anisotropic displacement parameters were refined for all atoms.

Main Results:

• Coarse colorless single crystals of LiLu[MoO4]2 were obtained as a byproduct.
• The compound crystallizes in the scheelite structure type (tetragonal, space group I41/a).
• A mixed occupancy of Li+ and Lu3+ cations in a 1:1 ratio was observed at the 4b Wyckoff position.

Conclusions:

• The crystal structure of lithium lutetium bis-[orthomolybdate(VI)] was successfully determined.
• The refinement with anisotropic displacement parameters provides a more detailed structural description compared to previous powder X-ray studies.