BaAg
2Hg
2O
4 was prepared by an oxygen high-pressure technique. Single crystal X-ray investigations led to tetragonal symmetry, space group D
4h
3
– P4/nbm;
a=6.793;
c=7.086 Å;
Z=2. Hg
2+ and Ag
+ show dumb-bell like coordination by oxygen whereas Ba
2+ ions are surrounded by 8 O
2– forming distorted cubes. The BaO
8-polyhedra distortions are discussed in respect to the incorporation of Hg
2+ ions into the BaAg
2O
4
2–
network.
Keywords Barium - Silver - Mercury - Oxide - High-pressure synthesis