Single crystals of Tl4Pd3Cl10 can be obtained by hydrothermal synthesis. Th
ey show tetragonal symmetry with lattice parameters a=15.956(1) Angstrom an
d c=14.146(1) Angstrom, Z=8 and space group I (4) over bar 2d (No. 122). Th
e atomic arrangement of Tl4Pd3Cl10 is explored by X-ray crystal structure a
nalysis. Tl4Pd3Cl10 is the first example of a new structural type with a hi
therto not isolated tetramer [(PdCl2Cl2/2)(4)](4-) group.