Mineralogy and Crystallography
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 RESEARCH PAPERS FROM OUR LAB:
  1. Gibbs, G.V., Hill, F.C., Boisen, M.B., Jr., and Downs, R.T. (1998) Power law relationships between bond length, bond strength and electron density distributions. Physics and Chemistry of Minerals 25, 585-590. ( pdf file )
  2. Gibbs, G.V., Boisen, M.B., Jr., Hill, F.C., Tamada, O., and Downs, R.T. (1998) SiO and GeO bonded interactions as inferred from the bond critical point properties of electron density distributions. Physics and Chemistry of Minerals, 25,574-584. ( pdf file )
  3. Jacobsen, S.D., Smyth, J.R., Swope, R.J., and Downs, R.T. (1998) Rigid-body character of the SO 4 groups in celestite, anglesite, and barite. Canadian Mineralogist, 36, 1045-1055. ( pdf abstract )
  4. Cohen, R. E., Fei, Y., Downs, R.T., Mazin, I.I., and Isaak, D.G. (1998) Magnetic collapse and the behavior of transition metal oxides: FeO at high pressures, in High-Pressure Materials Research, R. M. Wentzcovitch et al., eds., pp. 27-37, Symposium Proceedings Vol. 499, Materials Research Society, Warrendale, Pennsylvania. (pdf file)
  5. Prewitt, C.T. and Downs, R.T. (1998) High-Pressure Crystal Chemistry. Reviews in Mineralogy, 37, Ultrahigh-Pressure Mineralogy: Physics and Chemistry of the Earth’s Deep Interior, Russell J. Hemley, Editor. Mineralogical Society of America, Washington DC. (pdf file)
  6. Gibbs, G.V., Hill, F.C., Boisen, M.B., Jr., and Downs, R.T. (1999) Molecules as a basis for modeling the force field of silica. In Structure and Imperfections in Amorphous and Crystalline SiO2. Rod Devine, editor, John Wiley and Sons, Chapter 6, 151-163. (pdf file)
  7. Downs, R.T., Yang, H., Hazen, R.M., Finger, L.W., and Prewitt, C.T. (1999) Compressibility mechanisms of alkali feldspars: New data from reedmergnerite. American Mineralogist , 84, 333-340. ( pdf file )
  8. Sprague, A.L., Roush, T.L., Downs, R.T., Righter, K. (2000) Response to comment on "Comparison of laboratory emission spectra with Mercury telescopic data" by Melissa Lane. Icarus 143, 409-411. ( pdf file )
  9. Holl, C.M., Smyth, J.R., Lausten, H.M.S., Jacobsen, S.D., and Downs, R.T. (2000) Compression of witherite to 8 GPa and the crystal structure of BaCO 3 II. Physics and Chemistry of Minerals , 27, 467-473. ( pdf file )
  10. Hazen, R.M., and Downs, R.T. (2000) High-Temperature and High-Pressure Crystal Chemistry , Reviews in Mineralogy and Geochemistry, Volume 41. Robert M. Hazen and Robert T. Downs, Editors. Mineralogical Society of America, Washington DC.
  11. Angel, R.J., Downs, R.T., and Finger, L.W. (2000) High-temperature – high-pressure diffractometry. Reviews in Mineralogy and Geochemistry, 41, High-Temperature and High-Pressure Crystal Chemistry, Robert M. Hazen and Robert T. Downs, Editors. Mineralogical Society of America, Washington DC. (pdf file)
  12. Downs, R.T. (2000) Analysis of harmonic displacement factors. Reviews in Mineralogy and Geochemistry, 41, High-Temperature and High-Pressure Crystal Chemistry, Robert M. Hazen and Robert T. Downs, Editors. Mineralogical Society of America, Washington DC. (pdf file)
  13. Downs, R.T., and Heese, P.J. (2000) Animation of crystal structure variations with pressure, temperature and composition. Reviews in Mineralogy and Geochemistry, 41, High-Temperature and High-Pressure Crystal Chemistry, Robert M. Hazen and Robert T. Downs, Editors. Mineralogical Society of America, Washington DC. (pdf file)
  14. Hazen, R.M., Downs, R.T., and Prewitt, C.T. (2000) Principles of comparative crystal chemistry. Reviews in Mineralogy and Geochemistry, 41, High-Temperature and High-Pressure Crystal Chemistry, Robert M. Hazen and Robert T. Downs, Editors. Mineralogical Society of America, Washington DC. (pdf file)
  15. Thompson, R.M., and Downs, R.T. (2001) Quantifying distortion from ideal closest-packing in a crystal structure with analysis and application. Acta Crystallographica B57, 119-127. ( pdf file )
  16. Righter, K., and Downs, R.T. (2001) The crystal structures of synthetic Re- and PGE-bearing magnesioferrite spinels: Implications for impacts, accretion and the mantle. Geophysical Research Letters, 28, 619-622. (pdf file)
  17. Thompson, R.M., and Downs, R.T. (2001) The systematic generation of all nonequivalent closest-packed stacking sequences of length N using group theory. Acta Crystallographica, B57, 766-771. ( pdf file )
  18. Lager, G.A., Downs, R.T. Origlieri, M., and Garoutte, R. (2002) High-pressure single-crystal X-ray diffraction study of hydrogarnet: Evidence for a phase transition from Ia3d to I43d symmetry at 5 GPa. American Mineralogist 87, 642-647. ( pdf file )
  19. Downs, R.T., Gibbs, G.V., Boisen, M.B.Jr., and Rosso, K.M. (2002) A comparison of procrystal and ab initio representations of the electron-density distributions of minerals. Physics and Chemistry of Minerals 29, 369-385. ( pdf file )
  20. Downs, R.T. and Hall-Wallace, M. (2003) The American Mineralogist Crystal Structure Database. American Mineralogist 88, 247-250. ( pdf file )
  21. Downs, R.T. (2003) Topology of the pyroxenes as a function of temperature, pressure, and composition as determined from the procrystal electron density. American Mineralogist 88, 556-566. ( pdf file )
  22. Thompson, R.M. and Downs, R.T. (2003) Model pyroxenes I: Ideal pyroxene topologies. American Mineralogist 88, 653-666. ( pdf file )
  23. Denton, M.B., Sperline, R.P., Giles, J.H., Gilmore, D.A., Pommier, C.J.S., and Downs, R.T. (2003) Advances in the application of array detectors for improved chemical analysis, Part I. Comparison of qualitative analyses using large, computer-based Raman spectral libraries. Australian Journal of Chemistry 56, 117-131. ( pdf file )
  24. Downs, R.T. (2003) The Berry Medal for 2002 to Robert T. Downs. The Canadian Mineralogist 41, 243-245. ( pdf file )
  25. Gibbs, G.V., Cox, D.F., Boisen, M.B., Jr., Downs, R.T., and Ross, N.L. (2003) The electron localization function: a tool for locating favorable proton docking sites in the silica polymorphs. Physics and Chemistry of Minerals, 30, 305-316. ( pdf file )
  26. Origlieri, M.J., Downs, R.T., Thompson, R.M., Pommier, C.J.S., Denton, M.B., and Harlow, G.E. (2003) High-pressure crystal structure of kosmochlor, NaCrSi 2 O 6 , and systematics of anisotropic compression in pyroxenes. American Mineralogist, 88, 1025-1032. ( pdf file ) ( erratum )
  27. Wang, Z., Downs, R.T., Pischedda, V., Shetty, R., Saxena, S.K., Zha, C.S., Zhao, Y.S., Schiferl, D., and Waskowska, A. (2003) High-pressure X-ray diffraction and Raman spectroscopic studies of the tetragonal spinel CoFe 2 O 4 . Physical Review B 68, 094101. ( pdf file )
  28. Wang, Z., Zhao, Y., Schiferl, D., Zha, C.S., Downs, R.T., Sekine, T. (2003) Critical pressure for weakening of size-induced stiffness in spinel-structure Si 3 N 4 nanocrystals. Applied Physics Letters , 83, 3174-3176. ( pdf file )
  29. Pommier, C.J.S., Denton, M.B., and Downs, R.T. (2003) Raman spectroscopic study of spodumene (LiAlSi 2 O 6 ) through the pressure-induced phase change from C 2/ c to P 2 1 / c . Journal of Raman Spectroscopy , 34, 769-775. ( pdf file )
  30. Gibbs, G.V., Whitten, A.E., Spackman, M.A., Stimpfl, M., Downs, R.T., and Carducci, M.D. (2003) An exploration of theoretical and experimental electron density distributions and SiO bonded interactions for the silica polymorph coesite. Journal of Physical Chemistry B , ASAP Web Release Date: 01-Nov-2003; DOI: 10.1021/jp030583+ ( pdf file )
  31. Wang, Z., Zhao, Y., Schiferl, D., Qian, J., Downs, R.T., Mao, H-K., and Sekine, T. (2003) Threshold pressure for disappearance of size-induced effect in spinel-structure Ge3N4 nanocrystals. Journal of Physical Chemistry B Letters , ASAP Web Release Date: 02-Dec-2003; DOI: 10.1021/jp036436t ( pdf file )
  32. Ross, N.L. and Downs, R.T. (2003) "Stuffed" framework structures at high pressure. In NATO ASI Series: High-Pressure Crystallography , P.F. McMillan and A. Katrusiak, Eds., Kluwer Academic Press.
  33. Thompson, R.M., and Downs, R.T. (2004) Model pyroxenes II: Structural variation as a function of tetrahedral rotation. American Mineralogist 89, 614-628. ( pdf file )
  34. Bobev, S., and Tait, K.T. (2004) Methanol - inhibitor or promotor of the formation of gas hydrates from deuterated ice? American Mineralogist 89, 1208-1214. ( pdf file )
  35. Clark, C.M., and Downs, R.T. (2004) Using the American Mineralogist Crystal Structure Database in the classroom. Invited paper, Journal of Geoscience Education 51, 76-80. ( pdf file )
  36. Downs, R.T., and Hazen, R.M. (2004) Chiral indices of crystalline surfaces as a measure of enantioselective potential. Invited paper, Journal of Molecular Catalysis A: Chemical 216, 273-285. ( pdf file )
  37. Wang, Z, Zhao, Y., Schiferl, D., Zha, C.S., and Downs, R.T. (2004) Pressure induced increase of particle size and resulting weakening of elastic stiffness of CeO 2 nanocrystals. Applied Physics Letters 85, 124-126. ( pdf file )
  38. Wang, Z, Tait, K., Zhao, Y., Schiferl, D., Zha, C.S., Uchida, H., and Downs, R.T. (2004) Size-induced reduction of transition pressure and enhancement of bulk modulus of AlN nanocrystals. Journal of Physical Chemistry B 108, 11506-11508. ( pdf file )
  39. Wang, Z, Zhao, Y., Tait, K., Liao, X., Schiferl, D., Zha, C.S., Downs, R.T., Qian J., Zhu, Y., and Shen, T. (2004) A quenchable superhard carbon phase synthesized by cold compression of carbon nanotubes. Proceedings of the National Academy of Sciences of the United States of America 101, 13699-13702 ( pdf file )
  40. Le Bail, A., Chateigner, D., Chen, X., Ciriotti, M., Cranswick, L.M.D., Downs, R.T., Lutterotti, L., Rajan, H., Yokochi, A.F.T. (2004) Does open data better serve the crystallographic community? International Union of Crystallography Newsletter 12, 27.
  41. Tait, K.T., Hawthorne, F.C., Grice, J.D., Ottolini, L., and Nayak, V.K. (2005) Dellaventuraite, NaNa2(MgMn23+Ti4+Li)Si8O22O2, a new anhydrous amphibole from the Kajlidongri Manganese Mine, Jhabua District, Madhya Pradesh, India. American Mineralogist 90, 304-309. ( pdf file )
  42. Lager, G.A., Marshall, W.G., Liu, Z., and Downs, R.T. (2005) Re-examination of the hydrogarnet structure at high pressure using neutron powder diffraction and infrared spectroscopy. American Mineralogist 90, 639-644. (pdf file)
  43. Pommier, C.J.S., Downs, R.T., Stimpfl, M., Redhammer, G.J., and Denton, M.B. (2005) Raman and X-ray investigations of LiFeSi2O6 pyroxene under pressure. Journal of Raman Spectroscopy 36, 864-871. (pdf file)
  44. Dera, P., Prewitt, C. T., Jacobsen, S.D. (2005) Structure determination by single-crystal X-rat diffraction (SXD) at megabar pressures. Journal of Synchrotron Radiation 12, 547-548. (pdf file)
  45. Gunter, M.E., Downs, R.T., Bartelmehs, K.L., Evans, S.H., Pommier, C.J.S., Grow, J.S., Sanchez, M.S., and Bloss, F.D. (2005) Optic properties of centimeter-sized crystals determined in air with the spindle stage using EXCALIBRW. American Mineralogist 90, 1648-1654. (pdf file)
  46. Ding, Y., Xu, J., Prewitt, C.T., Hemley, R.J., Mao, H-K., Cowan, J.A., Zhang, J., Qian, J., Vogel, S.C., Lokshin, K., and Zhao, Y. (2005) Variable pressure-temperature neutron diffraction of wustite (Fe1-xO): Absence of long-range magnetic order to 20 GPa. Applied Physics Letters 86, 052505. (pdf file)
  47. Ding, Y., Liu, H., Xu, J., Prewitt, C.T., Hemley, R.J. and Mao, H-K. (2005) Zone-axis diffraction study of pressure-induced inhomogeneity in single-crystal Fe1-xO. Applied Physics Letters 87, 041912. (pdf file)
  48. Gibbs, G.V., Cox, D.F., Ross, N.L., Crawford T.D., Downs, R.T., and Burt, J.B. (2005) Comparison of the electron localization function and deformation electron density maps for selected earth materials. Journal of Physical Chemistry A 109, 10022-10027. (pdf file)
  49. Uchida, H., Lavina, B., Downs, R.T., and Chesley, J. (2005) Single-crystal X-ray diffraction of spinels from the San Carlos Volcanic Field, Arizona: Spinel as a geothermometer American Mineralogist 90, 1900-1908 (pdf file)
  50. Thompson, R.M., Downs, R.T., and Redhammer, G.J. (2005) Model pyroxenes III: Volume of C2/c pyroxenes at mantle P, T, and x. American Mineralogist 90, 1840-1851 (pdf file)
  51. Wang Z, Daemen L.L., Zhao, Y., Zha, C.S., Downs, R.T., Wang, X., Wang, Z.L., Hemley, R.J. (2005) Morphology-tuned wurtzite-type ZnS nanobelts. Nature Materials 4, 922-927. (pdf file)
  52. Gibbs G.V., Downs R.T., Prewitt C.T., Rosso K.M., Ross N.L., and Cox D.F. (2005) Electron density distributions calculated for the nickel sulfides millerite, vaesite and heazlewoodite and nickel metal: A case for the importance of Ni-Ni bond paths for electron transport. Journal of Physical Chemistry B 109, 21788-21795. (pdf file)
  53. Downs R.T. (2005) XtalDraw for Windows. Commission on Powder Diffraction, International Union of Crystallography Newsletter 30, 32-33. (pdf file)
  54. Rajan, H., Uchida, H., Bryan, D.L., Swaminathan, R., Downs, R.T., Hall-Wallace, M. (2006) Building the American Mineralogist Crystal Structure Database: A recipe for construction of a small Internet database. In Sinha, A.K. ed., Geoinformatics: Data to Knowledge: Geological Society of America Special Paper 397, 73-80. (pdf file)
  55. Gibbs, G.V., Cox, D.F., Crawford, T.D., Rosso, K.M., Ross, N.L., and Downs, R.T. (2006) Classification of metal-oxide bonded interactions based on local potential- and kinetic-energy densities. The Journal of Chemical Physics 124, 084704. (pdf file)
  56. Liermann, H.P., Downs, R.T., and Yang H. (2006) Site disorder revealed through Raman spectra from oriented single crystals: A case study on karooite (MgTi2O5) American Mineralogists 91, 790-793. (pdf file)
  57. Bindi, L., Downs, R.T., Harlow G.E., Safonov, O.G., Litvin, Y.A., Perchuk, L.L., Uchida, H., and Menchetti, S. (2006) Compressibility of synthetic potassium-rich clinopyroxene: In-situ high-pressure single-crystal X-ray study. American Mineralogists 91, 802-808. (pdf file)
  58. Wajima, T., Haga, M., Kuzawa, K., Ishimoto, H., Tamada, O., Ito, K., Nishiyama, T., Downs, R.T., and Rakovan, J.F. (2006) Zeolite synthesis from paper sludge ash at low temperature (90 °C) with addition of diatomite. Journal of Hazardous Materials B132, 244-252. (pdf file)
  59. Fritz E A, Origlieri M J, and Downs R T (2006) Triploidite from China. Gems & Gemology 42, 183-184. (pdf file)
  60. Schmidt G R, Reynard J, Yang H, Downs R T (2006) Tychite, Na6Mg2(SO4)(CO3)4: Structure analysis and Raman spectroscopic data. Acta Crystallographica E62, 207-209. (pdf file)
  61. Downs R T, Singh A K (2006) Analysis of deviatoric stress from nonhydrostatic pressure on a single crystal in a diamond anvil cell: The case of monoclinic aegirine, NaFeSi2O6. Journal of Physics and Chemistry of Solids 67, 1995-2000. (pdf file)
  62. Saini N L, Yang H, Saxena S K, and Bansil A (2006) Study of matter at extreme conditions, SMEC2005 Journal of Physics and Chemistry of Solids 67, 1913-1913 (pdf file)
  63. Righter K, Sutton S R, Newville M, Le L, Schwandt C S, Uchida H, Lavina B, Downs R T (2006) An experimental study of the oxidation state of vanadium in spinel and basaltic melt with implication for the origin of planetary basalt. American Mineralogist 91, 1643-1656. (pdf file)
  64. Yang H, Manoun B, Downs R T, Ganguly A, Barsoum M W (2006) Crystal chemistry of layered carbide, Ti3(Si0.43Ge0.57)C2. Journal of Physics and Chemistry of Solids 67, 2512-2516. (pdf file)
  65. Manoun B, Downs R T, and Saxena S K (2006) A high-pressure Raman spectroscopic study of hafnon, HfSiO4. American Mineralogist 91, 1888-1892. (pdf file)
  66. Yang H, Lu R, Downs R T, Costin G (2006) Goethite, α–FeO(OH), from single-crystal data. Acta Crystallographica E62, i250-i252. (pdf file)
  67. Ikuta D, Kawame N, Banno S, Hirajima T, Ito K, Rakovan J F, Downs R T, Tamada O (2007) First in situ X-ray diffraction identification of coesite and retrograde quartz on a glass thin section of an ultrahigh-pressure metamorphic rock and their crystal structure details. American Mineralogist 92, 57-63. (pdf file)
  68. Yang H, Downs R T (2007) Synthesis and crystal structure of Li0.52Mg0.96Sc0.52Si2O6 orthopyroxene. American Mineralogist 92, 225-228. (pdf file)
  69. Origlieri M J, Laetsch T A, Downs R T (2007) A note on the paragenesis of ottensite. The Mineralogical Record 38, 83-84 (pdf file)
  70. Uchida H, Downs R T, Thompson R M (2007) Reinvestigation of eakerite, Ca2SnAl2Si6O18(OH)2·2H2O: H-atom positions by single-crystal X-ray diffraction and correlation with Raman spectroscopic data. Acta Crystallographica E63, i47-i49 (pdf file)
  71. Yang H, Costin G, Keogh J, Lu R, Downs R T (2007) Cobaltaustinite, CaCo(AsO4)(OH) Acta Crystallographica E63, i53-i55 (pdf file)
  72. Gibbs G V, Cox D F, Rosso K M, Ross N L, Downs R T, Spackman M A (2007) Theoretical electron density distributions for Fe- and Cu-sulfide Earth materials: A connection between bond length, bond critical point properties, local energy densities, and bonded interactions. Journal of Physical Chemistry B 111, 1923-1931 (pdf file)
  73. Burt J B, Downs R T, Costin G (2007) Single-crystal X-ray refinement of wilkinsonite, Na2Fe2+4Fe3+2Si6O20. Acta Crystallographica E63, i122-i124 (pdf file)
  74. Estrada C F (2007) Changing the science of mineralogy: The use of Raman spectroscopy in mineral identification and the RRUFF project. Outcrop, Newsletter of the Rocky Mountain Association of Geologists 55, 1-8 (pdf file)
  75. Uchida H, Righter K, Lavina B, Nowell M M, Wright S I, Downs R T, Yang H (2007) Investigation of synthetic Mg1.3V1.7O4 spinel with MgO inclusions: Case study of a spinel with an apparently occupied interstitial site. American Mineralogist 92, 1031-1037 (pdf file)
  76. Yang H, Hubler D K, Lavina B, Downs R T, Costin G (2007) Tyrrellite, Cu(Co0.68Ni0.32)2Se4, isostructural with spinel. Acta Crystallographica C63, i73-i74 (pdf file)
  77. Yang H, Zwick J, Downs R T, Costin G (2007) Isokite, CaMg(PO4)F0.8(OH)0.2, isomorphous with titanite. Acta Crystallographica C63, i89-i90 (pdf file)
  78. Yang H, Li C, Jenkins R A, Downs R T, Costin G (2007) Kolbeckite, ScPO4·2H2O, isomorphous with metavariscite. Acta Crystallographica C63, i91-i92 (pdf file)
  79. Tenner T J, Lange R A, Downs R T (2007) The albite fusion curve re-examined: New experiments and the high-pressure density and compressibility of high albite and NaAlSi3O8 liquid. American Mineralogist 92, 1573-1585 (pdf file)
  80. Tait K T, Trouw F, Zhao Y, Brown C M, Downs R T (2007) Inelastic neutron scattering study of hydrogen in d8-THF/D2O ice clathrate. The Journal of Chemical Physics 127, 134505 (pdf file)
  81. Fritz E A, Laurs B M, Downs R T, Costin G (2007) Yellowish green diopside and tremolite from Merelani, Tanzania. Gems & Gemology 43, 146-148 (pdf file)
  82. Yang H, Sano J L, Eichler C, Downs R T, Costin G (2007) Iranite, CuPb10(CrO4)6(SiO4)2(OH)2, isomorphous with hemihedrite. Acta Crystallographica C63, i122-i124 (pdf file)
  83. Yang H, Downs R T, Costin G, Eichler C M (2007) The crystal structure of tvalchrelidzeite, Hg3SbAsS3, and a revision of its chemical formula. The Canadian Mineralogist 45, 1529-1533 (pdf file)
  84. Thompson R M, Downs R T (2008) The crystal structure of diopside at pressure to 10 GPa. American Mineralogist 93, 177-186 (pdf file)
  85. McCarthy A C, Downs R T, Thompson R M (2008) Compressibility trends of the clinopyroxenes, and in-situ high-pressure single-crystal X-ray diffraction study of jadeite. American Mineralogist 93, 198-209 (pdf file)
  86. Gibbs G V, Downs R T, Cox D F, Ross N L, Prewitt C T, Rosso K M, Lippmann T, Kirfel A (2008) Bonded interactions and the crystal chemistry of minerals: a review. Zeitschrift fur Kristallographie 223, 1-40 (pdf file)
  87. Yang H, Dembowski R F, Conrad P G, Downs R T (2008) Crystal structure and Raman spectrum of hydroxyl-bastnasite-(Ce), CeCO3(OH). American Mineralogist 93, 698-701 (pdf file)
  88. Gibbs G V, Downs R T, Cox D F, Ross N L, Boisen M B, Rosso K M (2008) Shared and closed-shell O-O interactions in silicates. Journal of Physical Chemistry A 112, 3693-3699 (pdf file)
  89. Dera P, Lavina B, Borkowski L A, Prakapenka V B, Sutton S R, Rivers M L, Downs R T, Boctor N Z, Prewitt C T (2008) High-pressure polymorphism of Fe2P and its implications for meteorites and Earth's core. Geophysical Research Letters 35, L10301 (pdf file)
  90. Nestola F, Boffa Ballaran T, Liebske C, Thompson R, Downs R T (2008) The effect of the hedenbergitic substitution on the compressibility of jadeite. American Mineralogist 93, 1005-1013 (pdf file)
  91. Yang H, Downs R T (2008) Crystal structure of glaucodot, (Co,Fe)AsS, and its relationships to marcasite and arsenopyrite. American Mineralogist 93, 1183-1186 (pdf file)

 
MEETINGS: back to top
  1. Downs, R.T., Yang, H., Hazen, R.M., and Finger, L.W. (1997) The high-pressure crystal chemistry of the alkali feldspars: New data from reedmergnerite, NaBSi 3 O 8 . EOS Transactions, AGU, Spring Meeting Supplement, 78 (17) S314
  2. Cohen, R.E., Fei, Y., Mazin, I.I., Downs, R.T., and Isaak, D.G. (1997) Phase transitions in transition metal oxides and unusual polytypism in high pressure FeO. EOS Transactions, AGU, Fall Meeting Supplement, 78 (46) F743
  3. Downs, R.T., Teter, D.M., and Gibbs, G.V. (1997) A Pro-crystal electron density analysis of potassium-oxygen bonding in microcline and KTP as a function of pressure. EOS Transactions, AGU, Fall Meeting Supplement, 78 (46) F754
  4. Downs, R.T. (1998) Computer graphics simulation of compression mechanisms in crystals. IUCR-HP98, Argonne, Abstracts, 21
  5. Thompson, R.M., and Downs, R.T. (1999) Quantitative analysis of the closest-packing of anions in mineral structures as a function of pressure, temperature, and compositions. EOS Transactions, AGU, Fall Meeting Supplement, 80 (46) F1107.
  6. Downs, R.T., Gibbs, G.V., and Boisen M.B., Jr. (1999) Topological analysis of the P21/c to C2/c transition in pyroxenes as a function of temperature and pressure. EOS Transactions, AGU, Fall Meeting Supplement, 80 (46) F1140.
  7. Righter, K., and Downs, R.T. (2000) Magnesioferrite spinel as the host phase for iridium and other highly siderophile elements at the cretaceous-tertiary boundary. Meteoritical Society Meeting. Meteoritics & Planetary Science 35: A136-A137, Supplement S Sep 2000
  8. Downs, R.T., Gibbs, G.V., Giovanni, M.K., Boisen, M.B.Jr., and Rosso, K.M. (2001) A comparison of procrystal and first-principles crystal electron density distributions with application to understanding the phase changes in pyroxenes. In Eleventh Annual V.M. Goldschmidt Conference, Abstract#3902, LPI Contribution No. 1088, Lunar and Planetary Institute, Houston (CD-ROM). May 20-24, Hot Springs, VA.
  9. Thompson, R.M., Downs, R.T., and Lienert, C. (2001) Ideal Pyroxene Topologies. In Eleventh Annual V.M. Goldschmidt Conference, Abstract#3149, LPI Contribution No. 1088, Lunar and Planetary Institute, Houston (CD-ROM). May 20-24, Hot Springs, VA.
  10. Thompson, R.M., Downs, R.T., and Teter, D.M. (2001) Packing systematics of stishovite. EOS Transactions, AGU, Fall Meeting Supplement, 82 (47) F1156. ( pdf abstract )
  11. Origlieri, M.J., Downs, R.T., and Harlow, G.E. (2001) Compression mechanism of the pyroxene kosmochlor. EOS Transactions, AGU, Fall Meeting Supplement, 82 (47) F1393. ( pdf abstract )
  12. Pommier, C.J.S., Denton, M.B., and Downs, R.T. (2002) Polarized Raman spectroscopic study of the pressure-induced phase change from C2/c to P21/c in spodumene. Pittcon 1747P, New Orleans, LA, March 17-22, 2002. ( pdf file )
  13. Lager, G.A., Marshall, W.G., and Downs, R.T. (2002) Keynote address: Re-examination of the hydrogarnet structure at high pressure using neutron powder methods: Comparison with single-crystal X-ray and theoretical results. 18th General Meeting of the International Mineralogical Association , 1-6 Sept, 2002, Edinburgh, Scotland. Programme With Abstracts, page 82.
  14. Origlieri, M.J., Thompson, R.M., Downs, R.T., and Gibbs, G.V. (2002) The relationship between compression anisotropy observed in the pyroxenes and oxide anion non-bonded repulsions. 18th General Meeting of the International Mineralogical Association , 1-6 Sept, 2002, Edinburgh, Scotland. Programme With Abstracts, page 71.
  15. Downs, R.T., and Hall-Wallace, M. (2002) A Database of Crystal Structures Published in the American Mineralogist and The Canadian Mineralogist and It?s Use as a Resource in the Classroom. 18th General Meeting of the International Mineralogical Association , 1-6 Sept, 2002, Edinburgh, Scotland. Programme With Abstracts, page 128.
  16. Thompson, R.M., and Downs, R.T. (2002) Model Pyroxenes and Transition Pathways. 18th General Meeting of the International Mineralogical Association , 1-6 Sept, 2002, Edinburgh, Scotland. Programme With Abstracts, page 85.
  17. Pommier, C.J.S., Denton, M.B., and Downs, R.T. (2003) Raman spectroscopic study of spodumene through the pressure-induced phase change from C2/c to P21/c. Pittcon 1730-3, Orlando, FL, March 9-14, 2003.
  18. Ross, N.L., and Downs, R.T. (2003) High-pressure crystal chemistry: ?Stuffed? framework structures at high-pressure. International School of Crystallography , High Pressure Crystallography, 4-15 June. Erice, Italy
  19. Hazen, R.M. and Downs, R.T. (2003) Chiral mineral surfaces and their chiral index. The Geological Society of America Annual Meeting, Seattle Washington. November 2-5, 2003. ( pdf abstract )
  20. Gibbs, G.V., Whitten, A., Spackman, M., Simpfl, M., Carducci, M., and Downs, R.T. (2003) The silica polymorph coesite: An exploration of the electron density. The Geological Society of America Annual Meeting, Seattle Washington. November 2-5, 2003. ( pdf abstract )
  21. McIntosh, B., Denton, M.B., Downs, R.T., Becker, D. (2003) Smart Raman instrument for Mars Science Laboratory. Mars Exploration Program Assessment Group, Sept 10-11, Jet Propulsion Laboratory, Pasadena, CA. ( pdf file )
  22. Uchida, H., and Downs, R.T. (2003) Single-crystal X-ray diffraction studies on spinels from the San Carlos Volcanic Field, Arizona. In Geochimica et Cosmochimica Acta 67, A497 Supplement, Goldschmidt Conference, Sept 7-12, Kurashiki Japan. ( pdf file )
  23. Tait K.T., Zhao, Y., and Downs, R.T. (2004) Investigations into the stability, morphology, and crystal structure of the coexistence of s-I and s-II methane-ethane and methane-propane clathrate hydrates: occurrence and geological implications. Lab Directed Research Dollars Review at LANSCE, Los Alamos, New Mexico. March 17, 2004.
  24. McIntosh, B. Denton, M.B., and Downs, R.T. (2004) Process Raman on Earth and research Raman on Mars - How are they related? Pittcon March 11, 2004. (Session: 24300-1000). Chicago, IL.
  25. Liermann H. P., Downs R. T., Yang H. (2004) Raman spectroscopy of order/disorder in pseudobrookite (MgTi2O5): Implication for the determination of the thermal history of planetary materials by remote sensing. 32nd IGC - Florence 2004.
  26. Hazen, R.M., Asthagiri, A., Teng, H., and Downs, R.T. (2004) Geochemical pathways to the origin of biochemical homochirality. Division of Geochemistry, American Chemical Society National Meeting, Philadelphia, PA, Aug 22-26. ( html file )
  27. Downs, R.T., Liermann, H.P., and Yang, H. (2004) The analysis of Mg and Ti order/disorder in pseudobrookite by Raman spectroscopy: Implications for the geological exploration of Mars. Geological Association of Canada - Mineralogical Association of Canada Annual Meeting, St. Catherines 2004. SS01-06.
  28. Asthagiri, A., Downs, R.T., and Hazen, R.M. (2004) Density functional theory modeling of interactions between amino acids and chiral mineral surfaces. Fall GSA, Denver, 9 Nov. 2004. Geological Society of America Abstracts with Programs, Vol. 36, No. 5, p. 338. ( html file )
  29. K. Tait, M. Hartl, D. Williams, C. Pantea, L.L. Daemen, Y. Zhao , & R. Downs (2005) Diffraction and spectroscopy of thorite and huttonite (ThSiO4), Geophysical Research Abstracts, Vol. 7, 10957, European Geophysical Union, Vienna, Austria, April 24-29, 2005.
  30. Lavina, B., Polozov, A., and Downs, R.T. (2005) Mg, Al, Si, Ca - bearing magnetite from Korshunovskoe, East Siberia. XX Congress of the International Union of Crystallography, 23-31 August, Florence, Italy
  31. Tait, K.T., Zhao, Y., Downs, R.T., Stern, L.A., & Kirby, S. (2005) Investigations into the stability, morphology and the crystal structure of structure I and II methane-ethane clathrate hydrates. International Conference on Gas Hydrates, June 13-16, 2005.
  32. Rajenski, K., Mogk, D., and Downs, R.T. (2005) Teaching mineralogy with crystal structure databases and visualization software: A digital resource collection. Goldschmidt Conference, Moscow, Idaho, May 20-25.
  33. McCarthy, A., Domanik, K., and Downs, R.T. (2005) Determining structural chemical formulae using the American Mineralogist Crystal Structure Database. Goldschmidt Conference, Moscow, Idaho, May 20-25.
  34. Yang, H., Lu, R., White, A., Downs, R.T., and Ma, Y. (2005) X-ray diffraction study of marokite (CaMn2O4) to 40 GPa. Abstracts of the Geological Society of America Annual Fall Meeting, Salt Lake City, 16-19 October 2005.
  35. Schmidt, G., Uchida H., Mooney, P., Lu, R., and Downs, R.T. (2005) Oriented crystal studies: Orienting the crystals Abstracts of the Geological Society of America Annual Fall Meeting, Salt Lake City, 16-19 October 2005.
  36. Dembowski, R.F., Mooney, P.R., Laetsch, T.A., Lu, R., and Downs, R.T. (2005) Orientation in Raman spectroscopy. Abstracts of the Geological Society of America Annual Fall Meeting, Salt Lake City, 16-19 October 2005.
  37. Mooney, P.R., Dembowski, R.F., Laetsch, T.A., Zwick, J., Downs, R.T., and Lu, R. (2005) RRUFF Project: Developing an integrated database of Raman and infrared spectra, X-ray diffraction and chemistry data for minerals. Abstracts of the Geological Society of America Annual Fall Meeting, Salt Lake City, 16-19 October 2005. (pdf of poster)
  38. Lu, R., Downs, R.T., Denton, M.B., and Rossman, G.R. (2005) Integrated database of Raman spectra, X-ray diffraction and chemistry data for minerals. Abstracts of the Geological Society of America Annual Fall Meeting, Salt Lake City, 16-19 October 2005.
  39. LeBail A, Chateigner D, Chen X, Ciriotti M, Cranswick L M D, Downs R T, Lutterotti L, Yokochi A F T (2005) COD (Crystallography Open Database) and PCOD (Predicted). Acta Crystallographica A61, C481-C481 (pdf file)
  40. Tait K T, Mao W L, Zhao Y, Trouw F R, Daemen L L, and Downs R T (2006) Gas hydrate experimental capabilities at the Los Alamos Neutron Scattering Center (LANSCE). LANSCE Basic Energy Sciences Review, Los Alamos, 21 March, 2006. link
  41. Mao W L, Tait K T, Zhao Y, Lokshin K, and Mao H-K (2006) Hydrogen storage in molecular compounds. LANSCE Basic Energy Sciences Review, Los Alamos, 21 March, 2006. link
  42. Downs R T (2006) The RRUFF Project: an integrated study of the chemistry, crystallography, Raman and infrared spectroscopy of minerals. Program and Abstracts of the 19th General Meeting of the International Mineralogical Association in Kobe, Japan. O03-13 link
  43. Origlieri M J, Downs R T, Carducci M D, Rosso K M, Gibbs G V (2006) Crystal structure and bonding in the new mineral AsSbO3. Program and Abstracts of the 19th General Meeting of the International Mineralogical Association in Kobe, Japan. O08-06 Pdf of abstract. PowerPoint Slides
  44. McCarthy A C, Downs R T, Lu R, Yang H (2006) Reexamination of yedlinite, Pb6(Cl,OH)6Cr3+(OH,O)8, using single-crystal X-ray diffraction and Raman spectroscopy, and redetermination of the chemical formula. Program and Abstracts of the 19th General Meeting of the International Mineralogical Association in Kobe, Japan. P08-12 link
  45. Ikuto D, Kawame N, Banno S, Hirajima T, Ito K, Rakovan J F, Downs R T, Tamada O (2006) First in situ X-ray identification of coesite and retrogressed quartz on a glass thin section of ultrahigh-pressure metamorphic rock and their crystal structure details. Program and Abstracts of the 19th General Meeting of the International Mineralogical Association in Kobe, Japan. P08-21 link
  46. Laetsch T A, Downs R T (2006) Software for identification and refinement of cell parameters from powder diffraction data of minerals using the RRUFF Project and American Mineralogist Crystal Structure Databases. Program and Abstracts of the 19th General Meeting of the International Mineralogical Association in Kobe, Japan. P08-25 link
  47. Tait K T, Trouw F R, Hehlen M P, Shapiro A H, Zhao Y, Downs R T (2006) Inelastic neutron study of THF+D2 clathrates. Program and Abstracts of the 19th General Meeting of the International Mineralogical Association in Kobe, Japan. P34-01 link
  48. Fong-Kee, G. (San Miguel High School), Thompson, R.M., and Downs, R.T. (2006) Mineralogy and Crystallography, Undergraduate Biology Research Program Summer Poster Session, University of Arizona.
  49. Thompson R M, Downs R T (2006) The crystal structure of diopside at pressure to 10 GPa. Eos Transactions, American Geophysical Union 87(52), Fall Meeting Supplement, Abstract MR21B-0018 link
  50. Ross N L, Gibbs G V, Downs R T, Prewitt C T, Rosso K M, Cox D F (2006) Electron density distributions for millerite, vaesite, heazlewoodite and Ni metal: A case for the importance of NiNi bond paths for electron transport. Eos Transactions, American Geophysical Union 87(52), Fall Meeting Supplement, Abstract MR43B-1086 link
  51. Gibbs G V, Cox D F, Rosso K M, Ross N L, Downs R T (2006) Bonded interactions in Fe and Cu sulfides; Do electroneutrality requirements hold in the classical sense for sulfides. Eos Transactions, American Geophysical Union 87(52), Fall Meeting Supplement, Abstract MR34A-08 PowerPoint Slides
  52. Dera P, Downs R T, Liermann H, Yang W (2006) Oscillation Laue Analysis (OLA) - A new crystal structure determination method for mineral physics. Eos Transactions, American Geophysical Union 87(52), Fall Meeting Supplement, Abstract MR24A-02 link
  53. Uchida H, Downs R T, Yang H (2006) Crystal-chemical investigation of kalsilite from San Venanzo, Italy, using single-crystal X-ray diffraction and Raman spectroscopy. Goldschmidt Conference Abstracts 2006, Geochimica et Cosmochimica Acta 70, A677-A680 link
  54. Downs R T, Thompson R M, Pommier C J S, McCarthy A C, Yang H (2007) Crystal chemistry of pyroxene compression. Study of Matter at Extreme Conditions Conference, Miami Beach, April 15-20, 2007
  55. Lu R, Konzett J, Frost D J, Yang H, Downs R T (2007) High-pressure Raman spectroscopic study of clinopyroxenes with 6-coordinated silicon. Study of Matter at Extreme Conditions Conference, Miami Beach, April 15-20, 2007
  56. Yang H, Konzett J, Downs R T (2007) Synthesis, crystal chemistry, and compressibility of a high-pressure phase (Ti0.50Zr0.26Cr0.10Mg0.14)O1.81 isostructural with cubic zirconia. Study of Matter at Extreme Conditions Conference, Miami Beach, April 15-20, 2007
  57. Thompson R M, McCarthy A C, Downs R T (2007) Crystal Chemical Controls on Equation of State. EOS Transactions AGU 88(52), Fall Meet. Suppl., Abstract DI44A-03 link
  58. Downs R T (2008) Minerals of the RRUFF project. Tucson Gem and Mineral Show Symposium, February 2008.
  59. Downs R T (2008) Compression Mechanisms of Minerals. Indiana University Geosciences Colloquim, April 2008.
  60. Downs R T (2008) Software from the RRUFF project databases, Raman and powder X-ray search/match routines for mineral identification. Compres Annual meeting, Colorado Springs, Colorado, June, 2008.

 
FUNDING: back to top
  • Capitalization, University of Arizona, (1996) $240,000.
  • A device to apply hydrostatic high-pressure to crystals (1999-2001) Faculty Small Grants Program, University of Arizona Foundation, $5000.
  • Compression mechanisms of upper mantle minerals (1999-2002) National Science Foundation EAR-9903104, $186,997.
  • Advancing Computational and Visualization Skills in Geosciences (2000-2002) National Science Foundation, $52,148. Joint, with M. Hall-Wallace (P.I.), R. F. Butler, P. Kresan, J. Pelletier.
  • Compression mechanisms of upper mantle minerals, Research Experience for Undergraduates (2000-2002) National Science Foundation, $12,500.
  • The crystal structure database and analysis tools project (2001-2004) National Science Foundation, $350,000.
  • University of Nevada at Las Vegas subcontract (2002) Development of Windows-based single crystal diffractometer software, Department of Energy, $34,815.
  • University of Nevada at Las Vegas subcontract (2002-2003) Development of Windows-based single crystal diffractometer software for Argonne National Labs' Advance Photon Source, Department of Energy, $83,669.
  • A high performance Raman spectroscopy system for Mars surface studies. (2003-2005) Co-PI: B. McIntosh (Hamilton Sundstrand Sensor Systems), M.B. Denton (U of Arizona), R.T. Downs (UofA) and W. Doyle (Axiom Analytical, Inc.) NASA, $1,491,770.
  • Clathrate Hydrates Science and Technology. (2003-2005) PI: Yusheng Zhao (Los Alamos) Co-PI: D.L. Bish, L.L. Daemen, A. Migliori, R.P. Currier, L.R. Pratt, P.C. Lichtner, D.D. Hickmott. Collaborators: H-K Mao, R. Hemley, J. Parise, R.T. Downs. Department of Energy $4,350,000.
  • Combination of private funding and matching funds from the College of Science for a new Bruker X8Apex single-crystal diffractometer and a Bruker D8Advance powder diffractometer plus laboratory renovations, $450,000.
  • Development of six new approaches for micro-focus single-crystal X-ray diffraction for materials structure research at synchrotrons. (2005-2008). National Science Foundation, $672,450. PIs: M F Nicol, M B Denton, P Dera, R T Downs, M L Rivers.
  • The RRUFF project: An integrated database of Raman and IR spectra, X-ray diffraction and chemistry data for minerals. (2004-2006) Private funding. $3.75M. PIs: R T Downs, M B Denton, G R Rossman.
  • Collaborative Proposal: A Study of Experimental and Theoretical Electron Density Distribution and Bonded Interactions for Sulfide Minerals (2006-2009). National Science Foundation EAR-0609906, $224,000. Joint with Charles T. Prewitt, Collaborative with Gibbs, Ross and Angel at Virginia Tech
  • The American Mineralogist Crystal Structure Database (2006-2009) National Science Foundation EAR-0622371. $399,308.
  • Fundamental diamond research. (2007-2008) Israel Diamond Institute: International Gemological Laboratory Ltd. $50,000.
  • Raman signatures and native fluorescence emissions of minerals: Systematic characterization of planetary surface materials. (2007-2008) Strategic University Research Partnership (SURP), Jet Propulsion Laboratory, NASA $100,000. PIs: P G Conrad, R T Downs, H Yang, L S Powers
  • Hybrid powder-single crystal X-ray diffraction instrument for planetary mineralogical analysis of unprepared samples. (2008) NASA SBIR Phase 1, $100,000. PIs: P Sarrazin, W Bruner, P C Dera, R T Downs

 
PRESS RELEASES: back to top

 

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Contact downs@geo.arizona.edu with any suggestions or corrections

 

The University Of Arizona Department Of Geosciences Mineralogy and Crystallography Dr. Robert T Downs