Published online by Cambridge University Press: 10 January 2013
Improved powder X-ray diffraction (XRD) data for liottite and sacrofanite, two members of the cancrinite group of minerals, were obtained using a rotating anode diffractometer. The cell parameters of liottite are a = 12.8575(3), c = 16.0905(6) Å, and the space group is ; the strongest reflections are at 4.834(38), 3.783(12), 3.714(100), 3.312(91), 2.784(13), 2.682(26), 2.470(17), and 2.143(27) Å. The cell parameters of sacrofanite are a = 12.8945(4) and c =74.2128(37) Å, and the possible space groups are P63/mmc, P63mc, and ; the strongest reflections are at 11.18(23), 3.757(25), 3.723(100), 3.488(27), 3.302(62), 2.651(31), 2.645(30), and 2.149(18) Å. The new data include an increased number of indexed peaks and empirical formulae that differ from the reference data (PDF 29-1187 and PDF 35-653, respectively).