Helvite Diffraction data computed using the structure from the paper listed below, along with the cell parameters refined from the powder pattern of R060621 Hassan I, Grundy H D American Mineralogist 70 (1985) 186-192 The crystal structures of helvite group minerals, (MnFeZn)8(Be6Si6O24)S2 CELL PARAMETERS: 8.3000 8.3000 8.3000 90.000 90.000 90.000 SPACE GROUP: P-43n ATOM X Y Z OCCUPANCY ISO(B) Mn 0.16870 0.16870 0.16870 1.000 0.647 O 0.13930 0.14000 0.41340 1.000 0.626 Be 0.25000 0.00000 0.50000 1.000 0.613 Si 0.25000 0.50000 0.00000 1.000 0.363 S 0.00000 0.00000 0.00000 1.000 1.105 X-RAY WAVELENGTH: 1.541838 BOUNDS ON TWO THETA: 0.0 90.0 LIMITS IMPOSED ON THE INDICES ARE: +/- 7 +/- 7 +/- 7 MAX. ABS. INTENSITY / VOLUME**2: 44.57631174 The INTENSITY cut off value is 1.00 2-THETA INTENSITY D-SPACING H K L 21.41 2.01 4.1500 2 0 0 23.97 8.46 3.7119 2 1 0 26.30 100.00 3.3885 2 1 1 30.46 2.58 2.9345 2 2 0 34.16 14.32 2.6247 3 1 0 37.54 4.30 2.3960 2 2 2 39.13 2.12 2.3020 3 2 0 40.67 19.63 2.2183 3 2 1 43.62 2.56 2.0750 4 0 0 46.42 23.69 1.9563 4 1 1 46.42 19.93 1.9563 3 3 0 49.09 5.89 1.8559 4 2 0 50.38 1.95 1.8112 4 2 1 51.65 1.14 1.7696 3 3 2 54.13 8.56 1.6942 4 2 2 56.54 2.57 1.6278 5 1 0 60.02 1.14 1.5413 4 3 2 61.16 5.88 1.5154 5 2 1 63.39 8.59 1.4672 4 4 0 65.58 4.45 1.4234 5 3 0 65.58 2.94 1.4234 4 3 3 67.74 3.37 1.3833 6 0 0 67.74 5.32 1.3833 4 4 2 69.86 6.17 1.3464 5 3 2 71.95 1.41 1.3123 6 2 0 74.02 8.40 1.2807 5 4 1 76.06 1.04 1.2513 6 2 2 82.11 1.11 1.1738 5 4 3 86.08 4.61 1.1295 6 3 3 86.08 2.92 1.1295 7 2 1 ================================================================================ XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.