Electron density and electrostatic properties of two peptide molecules: tyrosyl-glycyl-glycine monohydrate and glycyl-aspartic acid dihydrate

The electron density and electrostatic properties of Tyr-Gly-Gly and Gly-Asp molecules have been determined from high-resolution X-ray diffraction data at 123 K. Topological properties of the charge distribution are discussed and compared with those derived from other experimental studies on peptide molecules, and the characteristics of the (3,−1) critical points of the C=O, C—N, C—C bonds are analysed. Crystal data for Tyr-Gly-Gly: C13H17N3O5·H2O, Mr = 313, orthorhombic, P212121, Z = 4, T = 123 ± 2 K; lattice parameters: a = 7.984 (2), b = 9.535 (3), c = 18.352 (5) Å, V = 1397.1 (6) Å3, Dx = 1.49 g cm−3, μ = 1.2 cm−1 for λMo = 0.7107 Å. Crystal data for Gly-Asp: C6H10N2O5·2H2O, Mr = 212, orthorhombic, P212121, Z = 4, T = 123 ± 2 K; lattice parameters: a = 9.659 (1), b = 9.672 (1), c = 10.739 (1) Å, V = 1003.3 (4) Å3, Dx = 1.40 g cm−3, μ = 1.3 cm−1 for λMo = 0.7107 Å.

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Topological Analysis of the Electron Density Distribution in the Crystal of 8,9,10,12-Tetrafluoro-o-carborane on the Basis of the High-Resolution X-ray Diffraction Data at 120 K

Inorganic Chemistry ◽

10.1021/ic9807644 ◽

1998 ◽

Vol 37 (22) ◽

pp. 5834-5843 ◽

Cited By ~ 25

Author(s):

Konstantin A. Lyssenko ◽

Mikhail Yu. Antipin ◽

Viatcheslav N. Lebedev

Keyword(s):

High Resolution ◽

Density Distribution ◽

Electron Density ◽

Diffraction Data ◽

Electron Density Distribution ◽

Topological Analysis ◽

X Ray Diffraction ◽

X Ray

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Crystal data for ternary compounds of the system Cu–As2Se3

Journal of Applied Crystallography ◽

10.1107/s0021889887086588 ◽

1987 ◽

Vol 20 (4) ◽

pp. 323-323

Author(s):

C. A. Majid ◽

M. A. Hussain

Keyword(s):

Diffraction Data ◽

Lattice Parameters ◽

Structural Studies ◽

Crystal Data ◽

X Ray Diffraction ◽

Space Group ◽

X Ray ◽

Ternary Compounds

Structural studies of polycrystalline CuAsSe2, Cu3AsSe4 and Cu3AsSe3 are reported. These were found to be cubic with space group Pm{\bar 3}m and lattice parameters as follows: (1) CuAsSe2: a = 5.513(4) Å, V = 167.47(1) Å3, Z = 2; Dm = 5.56(6), Dx = 5.88 g cm−3. (2) Cu3AsSe4: a = 5.530(5) Å; V = 169.11(2) Å3; Z = 1; Dm = 5.51(5), Dx = 5.75 g cm−3. (3) Cu3AsSe3: a = 5.758(9) Å, V = 190.87(3) Å3, Z = 1, Dm = 5.03(9), Dx = 4.45 g cm−3. X-ray diffraction data using a Rigaku DMAX-IIIA diffractometer and Cu Kα radiation.

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Experimental electron density study of 1,2,4-triazole at 15 K. A comparison with ab initio-calculations

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.1997.212.3.213 ◽

1997 ◽

Vol 212 (3) ◽

Cited By ~ 11

Author(s):

P. Fuhrmann ◽

T. Koritsánszky ◽

P. Luger

Keyword(s):

Ab Initio Calculations ◽

Ab Initio ◽

Electron Density ◽

Diffraction Data ◽

Topological Properties ◽

X Ray Diffraction ◽

X Ray ◽

Experimental Electron Density ◽

Density Study

AbstractTopological properties and the Laplacian function of the electron density of 1,2,4-triazole have been determined from X-ray diffraction data collected at 15 K. 1,2,4-Triazole, C

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Experimental electron density and electrostatic properties ofpeptides by high resolution X-ray diffraction

Journal of Molecular Structure THEOCHEM ◽

10.1016/0166-1280(92)85013-b ◽

1992 ◽

Vol 255 ◽

pp. 241-260 ◽

Cited By ~ 15

Author(s):

C. Lecomte ◽

N. Ghermani ◽

V. Pichon-Pesme ◽

M. Souhassou

Keyword(s):

High Resolution ◽

Electron Density ◽

X Ray Diffraction ◽

X Ray ◽

Electrostatic Properties ◽

Experimental Electron Density

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Distribution and Topology of the Electron Density in an Aluminosilicate Compound from High-Resolution X-ray Diffraction Data: the Case of Scolecite

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768198003954 ◽

1998 ◽

Vol 54 (6) ◽

pp. 819-833 ◽

Cited By ~ 20

Author(s):

S. Kuntzinger ◽

N. E. Ghermani ◽

Y. Dusausoy ◽

C. Lecomte

Keyword(s):

High Resolution ◽

Density Distribution ◽

Electron Density ◽

Critical Points ◽

Diffraction Data ◽

Electron Density Distribution ◽

X Ray Diffraction ◽

X Ray ◽

And Topology ◽

Experimental Electron Density

The experimental electron density distribution in scolecite, CaAl2Si3O10.3H2O, has been derived from single-crystal high-resolution Ag Kα X-ray diffraction data. A statistical method based on the prediction matrix has been used to discuss the estimation of the valence populations (P val) in the kappa least-squares refinements. The densities on the Si—O—Si and Si—O—Al bridges have been characterized using the topology of the electron density through its Laplacian at the bond critical points. The Si—O and Al—O bond features are related to the atomic environment and to the Si—O—T geometries (T = Si, Al).

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Anharmonicity and isomorphic phase transition: a multi-temperature X-ray single-crystal and powder diffraction study of 1-(2′-aminophenyl)-2-methyl-4-nitroimidazole

IUCrJ ◽

10.1107/s2052252514002838 ◽

2014 ◽

Vol 1 (2) ◽

pp. 110-118 ◽

Cited By ~ 11

Author(s):

Agnieszka Poulain ◽

Emmanuel Wenger ◽

Pierrick Durand ◽

Katarzyna N. Jarzembska ◽

Radosław Kamiński ◽

...

Keyword(s):

Phase Transition ◽

High Resolution ◽

Electron Density ◽

Powder Diffraction ◽

Diffraction Data ◽

Large Temperature ◽

X Ray Diffraction ◽

X Ray ◽

Density Peaks ◽

Multipole Refinement

The harmonic model of atomic nuclear motions is usually enough for multipole modelling of high-resolution X-ray diffraction data; however, in some molecular crystals, such as 1-(2′-aminophenyl)-2-methyl-4-nitro-1H-imidazole [Paul, Kubicki, Jelschet al.(2011).Acta Cryst.B67, 365–378], it may not be sufficient for a correct description of the charge-density distribution. Multipole refinement using harmonic atom vibrations does not lead to the best electron density model in this case and the so-called `shashlik-like' pattern of positive and negative residual electron density peaks is observed in the vicinity of some atoms. This slight disorder, which cannot be modelled by split atoms, was solved using third-order anharmonic nuclear motion (ANM) parameters. Multipole refinement of the experimental high-resolution X-ray diffraction data of 1-(2′-aminophenyl)-2-methyl-4-nitro-1H-imidazole at three different temperatures (10, 35 and 70 K) and a series of powder diffraction experiments (20 ≤T≤ 300 K) were performed to relate this anharmonicity observed for several light atoms (N atoms of amino and nitro groups, and O atoms of nitro groups) to an isomorphic phase transition reflected by a change in thebcell parameter around 65 K. The observed disorder may result from the coexistence of domains of two phases over a large temperature range, as shown by low-temperature powder diffraction.

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Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

Zeitschrift für Naturforschung B ◽

10.1515/znb-2020-0091 ◽

2020 ◽

Vol 75 (8) ◽

pp. 765-768

Author(s):

Bohdana Belan ◽

Dorota Kowalska ◽

Mariya Dzevenko ◽

Mykola Manyako ◽

Roman Gladyshevskii

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Diffraction Data ◽

Binary Compound ◽

Lattice Parameters ◽

X Ray Diffraction ◽

Space Group ◽

X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

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Crystallographic features of ammonium fluoroelpasolites: dynamic orientational disorder in crystals of (NH4)3HfF7 and (NH4)3Ti(O2)F5

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520616017534 ◽

2017 ◽

Vol 73 (1) ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

Anatoly A. Udovenko ◽

Alexander A. Karabtsov ◽

Natalia M. Laptash

Keyword(s):

Single Crystal ◽

Electron Density ◽

Diffraction Data ◽

Central Atom ◽

X Ray Diffraction ◽

Dynamic Nature ◽

Orientational Disorder ◽

High Quality ◽

Structural Units ◽

X Ray

A classical elpasolite-type structure is considered with respect to dynamically disordered ammonium fluoro-(oxofluoro-)metallates. Single-crystal X-ray diffraction data from high quality (NH4)3HfF7 and (NH4)3Ti(O2)F5 samples enabled the refinement of the ligand and cationic positions in the cubic Fm \bar 3 m (Z = 4) structure. Electron-density atomic profiles show that the ligand atoms are distributed in a mixed (split) position instead of 24e. One of the ammonium groups is disordered near 8c so that its central atom (N1) forms a tetrahedron with vertexes in 32f. However, a center of another group (N2) remains in the 4b site, whereas its H atoms (H2) occupy the 96k positions instead of 24e and, together with the H3 atom in the 32f position, they form eight spatial orientations of the ammonium group. It is a common feature of all ammonium fluoroelpasolites with orientational disorder of structural units of a dynamic nature.

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Superstructure formation in the solid solution Sc3Pt3−xIn3 (x = 0–0.93)

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1515/zkri-2021-2007 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Nataliya L. Gulay ◽

Rolf-Dieter Hoffmann ◽

Jutta Kösters ◽

Yaroslav M. Kalychak ◽

Stefan Seidel ◽

...

Keyword(s):

Solid Solution ◽

Diffraction Data ◽

High Frequency ◽

Lattice Parameters ◽

X Ray Diffraction ◽

Space Group ◽

X Ray ◽

Platinum Content ◽

Arc Melting ◽

Modulation Vector

Abstract The equiatomic indide ScPtIn (ZrNiAl type, space group P 6 ‾ $‾{6}$ 2m) shows an extended solid solution Sc3Pt3–xIn3. Several samples of the Sc3Pt3–xIn3 series were synthesized from the elements by arc-melting and subsequent annealing, or directly in a high frequency furnace. The lowest platinum content was observed for Sc3Pt2.072(3)In3. All samples were characterized by powder X-ray diffraction and their lattice parameters and several single crystals were studied on the basis of precise single crystal X-ray diffractometer data. The correct platinum occupancy parameters were refined from the diffraction data. Decreasing platinum content leads to decreasing a and c lattice parameters. Satellite reflections were observed for the Sc3Pt3–xIn3 crystals with x = 0.31–0.83. These satellite reflections could be described with a modulation vector ( 1 3 , 1 3 , γ ) $\left(\frac{1}{3},\frac{1}{3},\gamma \right)$ ( γ = 1 2 $\gamma =\frac{1}{2}$ c* for all crystals) and are compatible with trigonal symmetry. The interplay of platinum filled vs. empty In6 trigonal prisms is discussed for an approximant structure with space group P3m1.

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