Ba(11)La(4)Br(34): a new barium lanthanum bromide

Area of Science:

• Inorganic Chemistry
• Solid-State Chemistry
• Crystallography

Background:

• The fluorite structure serves as a foundational model for many related inorganic compounds.
• Understanding complex bromide structures is crucial for materials science applications.

Purpose of the Study:

• To determine and describe the detailed crystal structure of barium lanthanum bromide (Ba-La-Br).
• To identify the building units and atomic arrangements within this novel compound.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to solve the crystal structure.
• Symmetry analysis and site occupancy refinement were performed.

Main Results:

• The barium lanthanum bromide structure is derived from the parent fluorite structure.
• The asymmetric unit comprises multiple barium and lanthanum sites, including a mixed-occupation site (1:1 Ba:La).
• Six distinct bromide sites were identified, with one exhibiting positional disorder.

Conclusions:

• The fundamental building units are edge-sharing polyhedral clusters of barium and lanthanum bromides.
• These clusters interconnect to form BaBr(8) square prisms and BaBr(10) groups, defining the overall framework.