Vapour growth and crystal data of the thio(seleno)-hypodiphosphates Sn2P2S6, Sn2P2Se6, Pb2P2Se6 and their mixed crystals

Abstract Single crystals (monoclinic polyhedra up to 5×5×5 mm 3 ) of the thio(seleno)-hypodiphosphates Sn 2 P 2 S 6 (yellowish-brown), Sn 2 P 2 Se 6 (black), Pb 2 P 2 S 6 (yellow) and Pb 2 P 2 Se 6 (dark-red) have been grown by vapour transport with iodine. The space group of Sn 2 P 2 S 6 is Pc, that of the other compounds P2 1 /c. All four compounds are completely miscible. Already small replacements of Sn by Pb (around 10 mole %) in Sn 2 P 2 S 6 change the space group to P2 1 /c. The pure as well as the 1:1 mixed-anion and mixed cation compounds were characterized by x-ray and thermal analysis.