The crystal structure of molybdomenite, PbSeO3

The crystal structure of molybdomenite (PbSeO3) from El Dragon mine (Bolivia) was refined in the space group P2(1)/m, using single-crystal X-ray diffraction data, to R-F = 0.049. The refined unit cell parameters are a = 4.5437(7), b = 5.5137(8), c = 6.634(l) Angstrom, 0 = 106.547(7)degrees. Molybdomenite is the lead selenite and is isostructural with scotlandite, the lead sulphite, PbSO3, with Se4+ playing the same role of S4+ in the latter. The structure of molybdomenite can be described as stacking of complex structural slabs along (100). In molybdomenite lead is ninefold coordinated (average Pb-O 2.78 Angstrom) and selenium form a trigonal pyramid with three oxygens (average Se-O 1.71 Angstrom)