Home A single-crystal neutron diffraction study of hambergite, Be2BO3(OH,F)
Article
Licensed
Unlicensed Requires Authentication

A single-crystal neutron diffraction study of hambergite, Be2BO3(OH,F)

  • G. Diego Gatta EMAIL logo , Garry J. McIntyre , Geoffrey Bromiley , Alessandro Guastoni and Fabrizio Nestola
Published/Copyright: April 2, 2015
Become an author with De Gruyter Brill

Abstract

The crystal chemistry and crystal structure of hambergite from the Anjanabonoina mine, Madagascar [Be2BO3(OH)0.96F0.04, Z = 8, a = 9.762(2), b = 12.201(2), c = 4.430(1) Å, V = 527.6(2) Å3, space group Pbca], were reinvestigated by means of electron microprobe analysis in wavelength-dispersive mode, secondary-ion mass spectrometry, single-crystal X-ray and neutron Laue diffraction. Chemical analyses show only a small amount of F (0.7-0.8 wt%, approximately 0.04 atoms per formula unit) substituting OH and no other substituent at a significant level. An anisotropic neutron structural refinement has been performed with final agreement index

R1 = 0.0504 for 76 refined parameters and 1430 unique reflections with F0 > 4σ(F0). The geometry of the hydroxyl group and hydrogen bonding in hambergite is now well defined: (1) only one independent H site was located and the O4-H distance, corrected for “riding motion,” is ∼0.9929 Å; (2) only one hydrogen bond appears to be energetically favorable, with a symmetry-related O4 as acceptor and with O4···O4 = 2.904(1) Å, H···O4 = 1.983(1) Å, and O4-H···O4 = 157.5(1)°. In other words, O4 sites act both as donor and as acceptor of the hydrogen bond, with a zigzag chain of H-bonds along [001]. The hydrogen-bonding scheme in hambergite found in this study is consistent with the pleochroic scheme of the infrared spectra previously reported, with two intensive modes ascribable to stretching vibrations of the hydroxyl group, at 3415 and 3520 cm-1, respectively. The two modes suggest at least two distinct hydrogen-bonding environments, ascribable to the presence of oxygen and fluorine at the acceptor site.

Received: 2012-5-17
Accepted: 2012-7-23
Published Online: 2015-4-2
Published in Print: 2012-11-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. Cation ordering over short-range and long-range scales in the MgAl2O4-CuAl2O4 series
  2. Blue spinel crystals in the MgAl2O4-CoAl2O4 series: Part I. Flux growth and chemical characterization
  3. Blue spinel crystals in the MgAl2O4-CoAl2O4 series: Part II. Cation ordering over short-range and long-range scales
  4. CO2 solubility in primitive martian basalts similar to Yamato 980459, the effect of composition on CO2 solubility of basalts, and the evolution of the martian atmosphere
  5. New structural features of the high-pressure synthetic sheet-disilicate Phase-X, K(2–x)Mg2Si2O7Hx
  6. Crystal structure refinements of borate dimorphs inderite and kurnakovite using 11B and 25Mg nuclear magnetic resonance and DFT calculations
  7. Hydrogen-bond system and dehydration behavior of the natural zeolite parthéite
  8. In situ dehydration behavior of zeolite-like cavansite: A single-crystal X-ray study
  9. LREE-redistribution among fluorapatite, monazite, and allanite at high pressures and temperatures
  10. A single-crystal neutron diffraction study of hambergite, Be2BO3(OH,F)
  11. Analyzing water contents in unexposed glass inclusions in quartz crystals
  12. The atomic structure of deuterated boyleite ZnSO4·4D2O, ilesite MnSO4·4D2O, and bianchite ZnSO4·6D2O
  13. Synthesis and crystal chemistry of Fe3+-bearing (Mg,Fe3+)(Si,Fe3+)O3 perovskite
  14. Mixed-layered structure formation during trans-vacant Al-rich illite partial dehydroxylation
  15. Structural regularities in 2M1 dioctahedral micas: The structure modeling approach
  16. Incorporation of Fe and Al in MgSiO3 perovskite: An investigation by 27Al and 29Si NMR spectroscopy
  17. In situ high-temperature Raman and FTIR spectroscopy of the phase transformation of lizardite
  18. Packing systematics and structural relationships of the new copper molybdate markascherite and related minerals
  19. On the origin of sellaite (MgF2)-rich deposits in Mg-poor environments
  20. Edgrewite Ca9(SiO4)4F2-hydroxyledgrewite Ca9(SiO4)4(OH)2, a new series of calcium humite-group minerals from altered xenoliths in the ignimbrite of Upper Chegem caldera, Northern Caucasus, Kabardino-Balkaria, Russia
  21. Whelanite, Cu2Ca6[Si6O17(OH)](CO3)(OH)3(H2O)2, an (old) new mineral from the Bawana mine, Milford, Utah
  22. 2M1-phlogopite from Black Hills (South Australia): The first case of configurational polytype in micas
  23. Oxy-chromium-dravite, NaCr3(Cr4Mg2)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup
  24. First-principles study of self-diffusion and viscous flow in diopside (CaMgSi2O6) liquid
  25. Browneite, MnS, a new sphalerite-group mineral from the Zakłodzie meteorite
  26. Mineralogical variation of silica induced by Al and Na in hydrothermal solutions
Downloaded on 24.9.2025 from https://www.degruyterbrill.com/document/doi/10.2138/am.2012.4232/html
Scroll to top button