<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Tl<sub>5</sub>Hg<sub>2</sub>Br<sub>5</sub>I<sub>4</sub> is prepared by fusion of TlBr and HgI<sub>2</sub> in a 5:2 molar ratio (evacuated quartz ampoule, 770 K, 6 h, cooling rate of 10 K/h).</p> </abstract>