First accurate location of two proton sites in tourmaline: a single-crystal neutron diffraction study of oxy-dravite

Simple item page
dc.contributor.authorGatta, GDen_AU
dc.contributor.authorBosi, Fen_AU
dc.contributor.authorMcIntyre, GJen_AU
dc.contributor.authorSkogby, Hen_AU
dc.date.accessioned2017-04-27T06:12:55Zen_AU
dc.date.available2017-04-27T06:12:55Zen_AU
dc.date.issued2014-06-03en_AU
dc.date.statistics2016-08-15en_AU
dc.description.abstractA single-crystal neutron diffraction study of oxy-dravite from Osarara (Narok district, Kenya) was performed. Intensity data were collected in Laue geometry at 10 K and anisotropic-structure refinement was undertaken. For the first time, two independent H sites were refined unambiguously for a mineral belonging to the tourmaline supergroup and located at 0.26, 0.13, 0.38 (labelled as H3, site occupancy ~98%) and at 0, 0, 0.9 (labelled as H1, site occupancy ~25%). The H-bonding scheme can thus be defined as follows: (1) the O at the O3 site acts as a ‘donor’ and the O at the O5 site as ‘acceptor’, the refined O3–H3 bond distance is 0.972(2) Å (and 0.9946 Å corrected for “riding motion”), H3⋯O5 = 2.263(2) Å, O3⋯O5 = 3.179(1) Å and O3–H3⋯O5 = 156.6(1)°; (2) the oxygen at the O1 site acts as a ‘donor’ and the O atoms at O4 and O5 as ‘acceptors’, the refined O1–H1 bond distance is 0.958(8) Å (and 0.9833 Å corrected for “riding motion”), H1⋯O4 = 2.858(6) Å, O1⋯O4 = 3.378(1) Å and O1–H1⋯O4 = 115.12(1)°, whereas H1⋯O5 = 2.886(6) Å, O1⋯O5 = 3.444(1) Å and O1–H1⋯O5 = 118.23(1)°. A further test refinement was performed with the H1 site out of the three-fold axis (at 0.02, 0.01, 0.90); this leads to O1–H1 = 0.995(8) Å (and 1.0112 Å corrected for “riding motion”), H1⋯O4 = 2.747(6) Å and O1–H1⋯O4 = 121.7(4)°, whereas H1⋯O5 = 2.654(9) Å and O1–H1⋯O5 = 136.5(6)°. Bond-valence analysis shows that the H-bonding strength involving O3 is stronger than that involving O1: ~0.11 and <0.05 valence units, respectively. The refined angle between the O3–H3 vector and [0001] is 3.40(9)°. Such a small angle is in line with a pleochroic scheme for the OH-stretching absorption bands measured by infrared spectroscopy. © The Mineralogical Society of Great Britain & Ireland.en_AU
dc.identifier.citationGatta, G. D., Bosi, F., McIntyre, G. J., & Skogby, H. (2014). First accurate location of two proton sites in tourmaline: a single-crystal neutron diffraction study of oxy-dravite. Mineralogical Magazine, 78(3), 681-692. doi:10.1180/minmag.2014.078.3.15en_AU
dc.identifier.govdoc6942en_AU
dc.identifier.issn1471-8022en_AU
dc.identifier.issue3en_AU
dc.identifier.journaltitleMineralogical Magazineen_AU
dc.identifier.pagination681-692en_AU
dc.identifier.urihttp://dx.doi.org/10.1180/minmag.2014.078.3.15en_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/8638en_AU
dc.identifier.volume78en_AU
dc.language.isoenen_AU
dc.publisherMineralogical Societyen_AU
dc.subjectNeutron diffractionen_AU
dc.subjectDataen_AU
dc.subjectSpectroscopyen_AU
dc.subjectAtomsen_AU
dc.subjectTourmalineen_AU
dc.subjectOxygenen_AU
dc.titleFirst accurate location of two proton sites in tourmaline: a single-crystal neutron diffraction study of oxy-draviteen_AU
dc.typeJournal Articleen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Journal Articles