The crystal structure of phlogopite by neutron diffraction

SummaryThe positions of all the atoms including hydrogen have been found by a partial three-dimensional single-crystal neutron-diffraction study in which about one-third of the reflections in the reciprocal sphere to 1·5 Å were measured. The hydroxyl group is perpendicular to the plane of the silicate sheets. The fluorine content of this phlogopite is enough to occupy 25 % of the (OH, F) sites. Site occupancy refinement suggests that there is a small deficiency of hydrogen at the remaining sites and that the two crystallographically different octahedral sites are fully occupied by the same proportions of Mg, Ti, Fe, and Ca.

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Thermal Evolution of the Crystal Structure of the Rhombohedral Bi0.75Sr0.25O1.375 Phase: A Single Crystal Neutron Diffraction Study

Journal of Solid State Chemistry ◽

10.1006/jssc.1994.1255 ◽

1994 ◽

Vol 112 (1) ◽

pp. 1-8 ◽

Cited By ~ 46

Author(s):

D. Mercurio ◽

J.C. Champarnaud-Mesjard ◽

B. Frit ◽

P. Conflant ◽

J.C. Boivin ◽

...

Keyword(s):

Crystal Structure ◽

Neutron Diffraction ◽

Single Crystal ◽

Diffraction Study ◽

Thermal Evolution ◽

Neutron Diffraction Study

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A single-crystal neutron-diffraction study of the crystal structure of tetragonal KH2PO4at high pressure (approximately 14 kbar)

Journal of Physics C Solid State Physics ◽

10.1088/0022-3719/13/21/009 ◽

1980 ◽

Vol 13 (21) ◽

pp. 4035-4051 ◽

Cited By ~ 24

Author(s):

G M Meyer ◽

R J Nelmes ◽

C Vettier

Keyword(s):

Crystal Structure ◽

High Pressure ◽

Neutron Diffraction ◽

Single Crystal ◽

Diffraction Study ◽

Neutron Diffraction Study

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Single crystal neutron diffraction study of the phase transition in (NH4)H5(PO4)2

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.218.7.470.20708 ◽

2003 ◽

Vol 218 (7) ◽

Cited By ~ 1

Author(s):

Sergej I. Troyanov ◽

E. V. Kosterina ◽

A. Loose ◽

M. Reehuis ◽

Erhard Kemnitz

Keyword(s):

Crystal Structure ◽

Phase Transition ◽

Neutron Diffraction ◽

Single Crystal ◽

Diffraction Study ◽

Neutron Diffraction Study

AbstractThe crystal structure of NH

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

Mineralogical Magazine ◽

10.1180/minmag.2014.078.3.15 ◽

2014 ◽

Vol 78 (3) ◽

pp. 681-692 ◽

Cited By ~ 14

Author(s):

G. D. Gatta ◽

F. Bosi ◽

G. J. McIntyre ◽

H. Skogby

Keyword(s):

Neutron Diffraction ◽

Single Crystal ◽

Diffraction Study ◽

Structure Refinement ◽

Site Occupancy ◽

Bond Distance ◽

Neutron Diffraction Study ◽

Fold Axis ◽

Absorption Bands ◽

First Time

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.

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Location of the proton in the very strong OHO hydrogen bonds in 2-(N,N-diethylamino-N-oxymethyl)-4,6-dichlorophenol. A single crystal neutron diffraction study

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.1997.212.2.126 ◽

1997 ◽

Vol 212 (2) ◽

Cited By ~ 1

Author(s):

H. Ptasiewicz-Bak ◽

R. Tellgren ◽

I. Olovsson ◽

A. Koll

Keyword(s):

Crystal Structure ◽

Hydrogen Bond ◽

Hydrogen Bonds ◽

Neutron Diffraction ◽

Single Crystal ◽

Diffraction Study ◽

Neutron Diffraction Study ◽

Crystallographic Symmetry ◽

O 175.8 ◽

Oxygen Atoms

AbstractThe crystal structure of 2-(N,N-diethylamino-N-oxymethyl)-4,6-dichlorophenol contains two slightly different molecules A and B, both with very strong intramolecular O … H … O hydrogen bonds, with O–O distances 2.423(4) Å and 2.400(5) Å, respectively, and with no crystallographic symmetry. The bridging oxygen atoms are also chemically different, O1 is bonded to carbon and O2 to nitrogen. The single crystal neutron diffraction study shows quite unambiguously that the proton in both cases is located slightly off-centred. In the A molecule O1–H = 1.167(6) Å, H–O2 = 1.258(6) Å and the angle O–H–O = 175.8(5)°; in the B molecule O1–H = 1.186(7) Å, H–O2 = 1.214(7) Å and the angle O–H–O = 176.5(5)°. As expected the proton is thus closer to the centre in the slightly shorter hydrogen bond.

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