Neutron Diffraction Study of the Structure and Thermal Motion of Phosphonium Bromide

1971 ◽  
Vol 54 (5) ◽  
pp. 1968-1973 ◽  
Author(s):  
L. W. Schroeder ◽  
J. J. Rush
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
Thermal Motion ◽  
Phosphonium Bromide

Xenon Tetrafluoride Molecule and Its Thermal Motion: A Neutron Diffraction Study

Science ◽  
1963 ◽  
Vol 139 (3560) ◽  
pp. 1208-1209 ◽  
Author(s):  
J. H. Burns ◽  
P. A. Agron ◽  
H. A. Levy
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
Thermal Motion

scholarly journals Single-Crystal Neutron Diffraction Study of Diammonium Hexaaquacopper Disulfate at 15 and 293 K. Investigation of Anharmonic Thermal Motion.

1994 ◽  
Vol 48 ◽  
pp. 800-809 ◽  
Author(s):  
Bo Brummerstedt Iversen ◽  
Finn Krebs Larsen ◽  
Philip A. Reynolds ◽  
Brian N. Figgis ◽  
Synnøve Liaaen-Jensen ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
Thermal Motion

Neutron diffraction study of the atomic and molecular motion in hexamethylenetetramine

1970 ◽  
Vol 26 (2) ◽  
pp. 263-271 ◽  
Author(s):  
J. A. K. Duckworth ◽  
B. T. M. Willis ◽  
G. S. Pawley
Keyword(s):  
Neutron Diffraction ◽  
Rigid Body ◽  
Diffraction Study ◽  
Probability Density ◽  
Molecular Motion ◽  
Lone Pair ◽  
Neutron Diffraction Study ◽  
Probability Density Functions ◽  
Thermal Motion ◽  
Density Functions

An accurate neutron diffraction study has been carried out on a single-crystal of hexamethylenetetramine and the measured Bragg intensities have been analysed for the effects of thermal motion. Four different models of the thermal motion have been used in a least-squares refinement of the data: (1) conventional model with ellipsoidal atomic probability density functions; (2) cumulant expansion model with the thermal motion of each atom represented by both second and third cumulant coefficients; (3) as model (1) but including the restriction imposed on the temperature factors by assuming rigid-body molecular motion; (4) as model (2) but including the rigid-body restriction. The best fit is given by model (2), which takes into account deviations from the ellipsoidal atomic probability density functions brought about by libration. Of the rigid-body models, refinement is better for (4) than for (3). Two parameters only, (u 2) and (ω 2) of paper I (Willis & Pawley, Acta Cryst. (1970), A26, 254) are needed to specify the atomic thermal motions for models (3) and (4), whereas nine parameters are required for model (1) and twenty for model (2). The lone-pair electrons of the nitrogen atom have been detected by combining, in a difference Fourier synthesis, the present data with the X-ray measurements of Becka & Cruickshank (Proc. Roy. Soc. A (1963), 273, 435).

Interlayer interactions in M(OH)2: a neutron diffraction study of Mg(OH)2

1996 ◽  
Vol 52 (1) ◽  
pp. 82-86 ◽  
Author(s):  
L. Desgranges ◽  
G. Calvarin ◽  
G. Chevrier
Keyword(s):  
Neutron Diffraction ◽  
Temperature Dependence ◽  
Diffraction Study ◽  
Magnesium Hydroxide ◽  
Room Temperature ◽  
Interlayer Spacing ◽  
Neutron Diffraction Study ◽  
Thermal Motion ◽  
Interatomic Distances ◽  
Atom Model

Magnesium hydroxide, Mg(OH)2: Mr = 58.3, trigonal, P{\bar 3}m1, a = 3.148 (1), c = 4.779 (2) Å, V = 41.015 Å3, Dx = 2.36 g cm−3 at room temperature; a = 3.145 (1), c = 4.740 (2) Å, V = 40.602 Å3, Dx = 2.39 g cm−3 at 70 K; Z = 1, λ = 0.8330 (5) Å, μ = 1.78 cm−1, F(000) = 9.503 fm; final R = 2.42, wR = 2.40, S = 3.22 for 82 unique reflections at room temperature; R = 1.84, wR = 1.82, S = 2.54 for 81 unique reflections at 70 K. Refinements have been carried out using anisotropic thermal coefficients for all atoms. To interpret the very large thermal motion of the H atom, subsequent refinements have been carried out with an anharmonic model and with a three-site split-atom model, and results are compared with those previously reported for Ca(OH)2. By comparing the interatomic distances O...O, H...H and H...O in the interlayer spacing of Mg(OH)2 and Ca(OH)2, as well as their temperature dependence, the nature and the strength of interlayer interactions in both compounds are discussed.

Neutron diffraction study of nickel zirconium hydride

1964 ◽  
Vol 25 (5) ◽  
pp. 451-453 ◽  
Author(s):  
S.W. Peterson ◽  
V.N. Sadana ◽  
W.L. Korst
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
Zirconium Hydride
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