Akermanite Yang H, Hazen R M, Downs R T, Finger L W Physics and Chemistry of Minerals 24 (1997) 510-519 Structural change associated with the incommensurate-normal phase transition in akermanite, Ca2MgSi2O7, at high pressure Sample: P = 0.0 GPa _database_code_amcsd 0008030 CELL PARAMETERS: 7.8338 7.8338 5.0082 90.000 90.000 90.000 SPACE GROUP: P-42_1m X-RAY WAVELENGTH: 1.541838 Cell Volume: 307.345 Density (g/cm3): 2.946 MAX. ABS. INTENSITY / VOLUME**2: 22.00695696 RIR: 2.433 RIR based on corundum from Acta Crystallographica A38 (1982) 733-739 2-THETA INTENSITY D-SPACING H K L Multiplicity 16.00 9.67 5.5393 1 1 0 4 17.71 1.76 5.0082 0 0 1 2 21.05 7.18 4.2196 1 0 1 8 22.70 2.84 3.9169 2 0 0 4 23.95 10.56 3.7150 1 1 1 4 25.42 4.05 3.5034 2 1 0 8 28.94 23.08 3.0853 2 0 1 8 31.16 100.00 2.8707 2 1 1 8 32.32 3.62 2.7697 2 2 0 4 35.86 1.72 2.5041 0 0 2 2 36.26 16.27 2.4773 3 1 0 8 37.09 5.12 2.4237 2 2 1 4 37.71 6.17 2.3852 1 0 2 8 38.90 7.01 2.3154 3 0 1 8 39.49 2.36 2.2818 1 1 2 4 40.63 1.54 2.2205 3 1 1 8 44.47 12.06 2.0372 2 1 2 8 45.51 2.30 1.9932 3 2 1 8 46.36 5.47 1.9584 4 0 0 4 47.88 6.22 1.9000 4 1 0 8 49.04 3.95 1.8575 2 2 2 4 49.36 9.81 1.8464 3 3 0 4 51.44 8.73 1.7764 4 1 1 8 51.92 18.58 1.7611 3 1 2 8 52.22 5.63 1.7517 4 2 0 8 52.85 2.96 1.7325 3 3 1 4 56.04 2.25 1.6411 3 2 2 8 57.67 1.69 1.5984 1 1 3 4 60.26 1.31 1.5357 2 0 3 8 61.53 4.25 1.5070 2 1 3 8 62.50 1.20 1.4861 3 3 2 4 63.32 2.52 1.4688 5 1 1 8 65.26 4.33 1.4298 2 2 3 4 66.47 2.39 1.4065 3 0 3 8 66.99 8.49 1.3970 5 2 1 8 67.65 2.72 1.3848 4 4 0 4 70.56 1.59 1.3347 4 4 1 4 70.96 1.29 1.3282 4 3 2 8 72.38 2.89 1.3056 6 0 0 4 75.60 1.07 1.2579 5 2 2 8 75.86 3.80 1.2541 4 1 3 8 76.01 1.06 1.2521 0 0 4 2 77.01 1.93 1.2383 3 3 3 4 79.75 1.69 1.2024 6 2 1 8 80.88 2.06 1.1885 5 4 1 8 81.26 1.03 1.1839 5 3 2 8 83.50 1.76 1.1577 6 0 2 8 84.88 1.27 1.1424 4 3 3 8 85.99 2.18 1.1305 5 1 3 8 86.13 1.17 1.1290 3 0 4 8 87.24 1.08 1.1174 3 1 4 8 89.32 1.07 1.0967 5 2 3 8 ================================================================================ XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.