Pyroxene-ideal Thompson R M, Downs R T American Mineralogist 88 (2003) 653-666 Model pyroxenes I: Ideal pyroxene topologies Pyroxene #20a based on stacking sequence ABABCACBACBC Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience. _database_code_amcsd 0003024 CELL PARAMETERS: 19.5959 6.0000 3.4641 90.000 90.000 90.000 SPACE GROUP: P2/c X-RAY WAVELENGTH: 1.541838 Cell Volume: 407.293 Density (g/cm3): 9.821 MAX. ABS. INTENSITY / VOLUME**2: 18.23790671 RIR: 0.605 RIR based on corundum from Acta Crystallographica A38 (1982) 733-739 2-THETA INTENSITY D-SPACING H K L Multiplicity 20.10 1.19 4.4188 3 1 0 4 27.31 4.03 3.2660 6 0 0 2 29.78 8.56 3.0000 0 2 0 2 30.14 1.63 2.9654 -1 1 1 4 30.14 6.53 2.9654 1 1 1 4 31.18 4.09 2.8685 -2 1 1 4 31.18 3.72 2.8685 2 1 1 4 32.85 2.91 2.7262 3 1 1 4 32.85 2.91 2.7262 -3 1 1 4 40.02 2.09 2.2528 -1 2 1 4 40.02 1.05 2.2528 1 2 1 4 40.84 28.25 2.2094 6 2 0 4 40.84 19.76 2.2094 -2 2 1 4 40.84 4.94 2.2094 2 2 1 4 42.18 4.09 2.1423 3 2 1 4 42.18 4.09 2.1423 -3 2 1 4 44.00 4.20 2.0580 4 2 1 4 44.00 1.05 2.0580 -4 2 1 4 44.25 93.24 2.0467 9 1 0 4 44.25 5.41 2.0467 7 1 1 4 44.25 1.35 2.0467 -7 1 1 4 46.25 35.38 1.9629 -5 2 1 4 47.95 11.51 1.8974 -8 1 1 4 48.89 1.51 1.8628 6 2 1 4 48.89 1.51 1.8628 -6 2 1 4 51.89 18.98 1.7621 7 2 1 4 51.89 2.46 1.7621 -7 2 1 4 53.08 3.01 1.7253 -1 3 1 4 53.08 12.04 1.7253 1 3 1 4 53.08 6.02 1.7253 -1 0 2 2 53.08 1.51 1.7253 1 0 2 2 53.74 13.59 1.7056 -2 3 1 4 53.74 8.49 1.7056 2 3 1 4 53.74 4.25 1.7056 -2 0 2 2 53.74 6.79 1.7056 2 0 2 2 54.84 10.45 1.6742 3 3 1 4 54.84 10.45 1.6742 -3 3 1 4 54.84 5.22 1.6742 3 0 2 2 54.84 5.22 1.6742 -3 0 2 2 55.20 6.15 1.6641 -8 2 1 4 55.20 1.54 1.6641 8 2 1 4 56.06 7.77 1.6406 10 1 1 4 56.06 1.82 1.6406 -2 1 2 4 56.06 7.28 1.6406 2 1 2 4 56.34 4.27 1.6330 12 0 0 2 56.34 6.63 1.6330 4 3 1 4 56.34 7.55 1.6330 -4 3 1 4 56.34 3.78 1.6330 4 0 2 2 56.34 3.31 1.6330 -4 0 2 2 57.12 1.57 1.6126 3 1 2 4 57.12 1.57 1.6126 -3 1 2 4 58.24 3.32 1.5842 5 3 1 4 58.24 13.27 1.5842 -5 3 1 4 58.24 1.66 1.5842 -5 0 2 2 58.24 6.63 1.5842 5 0 2 2 58.58 1.69 1.5757 -4 1 2 4 60.44 1.29 1.5317 -11 1 1 4 60.44 14.64 1.5317 5 1 2 4 65.22 1.18 1.4304 7 1 2 4 65.22 8.73 1.4304 -7 1 2 4 66.07 17.94 1.4142 -8 3 1 4 66.07 8.97 1.4142 8 0 2 2 66.78 1.63 1.4009 -11 2 1 4 68.12 3.14 1.3765 8 1 2 4 68.88 5.14 1.3631 6 4 0 4 68.88 3.77 1.3631 -2 4 1 4 71.33 1.19 1.3222 -7 2 2 4 72.83 7.77 1.2987 -5 4 1 4 72.89 5.14 1.2978 10 3 1 4 72.89 2.57 1.2978 -10 0 2 2 74.12 2.68 1.2792 8 2 2 4 74.30 2.51 1.2765 15 1 0 4 75.77 2.13 1.2554 13 2 1 4 76.75 4.61 1.2418 -11 3 1 4 76.75 1.15 1.2418 11 3 1 4 76.75 2.30 1.2418 11 0 2 2 77.23 4.93 1.2352 7 4 1 4 79.95 1.94 1.2000 -8 4 1 4 80.67 2.32 1.1911 -10 2 2 4 87.27 1.35 1.1172 -13 1 2 4 ================================================================================ XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.