Structure, Elastic Constants and XRD Spectra of Extended Solids under High Pressure

MRS Advances ◽  
2018 ◽  
Vol 3 (8-9) ◽  
pp. 499-504 ◽  
Author(s):  
I.G. Batyrev ◽  
S.P. Coleman ◽  
J.A. Ciezak-Jenkins ◽  
E. Stavrou ◽  
J.M. Zaug
Keyword(s):  
Elastic Constants ◽  
Energetic Materials ◽  
Density Functional ◽  
Three Dimensional ◽  
Peak Position ◽  
X Ray Diffraction ◽  
Covalent Bonds ◽  
X Ray ◽  
Extended Solids ◽  
Xrd Patterns

ABSTRACTWe present results of evolutionary simulations based on density functional calculations of a potentially new type of energetic materials called extended solids: P-N and N-H. High-density structures with covalent bonds generated using variable and fixed concentration methods were analysed in terms of thermo-dynamical stability and agreement with experimental X-ray diffraction (XRD) spectra. X-ray diffraction spectra were calculated using a virtual diffraction algorithm that computes kinematic diffraction intensity in three-dimensional reciprocal space before being reduced to a two-theta line profile. Calculated XRD patterns were used to search for the structure of extended solids present at experimental pressures by optimizing data according to experimental XRD peak position, peak intensity and theoretically calculated enthalpy. Elastic constants has been calculated for thermodynamically stable structures of P-N system.

scholarly journals Theoretical and X-ray diffraction studies of organic photovoltaic compounds

2014 ◽  
Vol 70 (a1) ◽  
pp. C996-C996
Author(s):  
Abdelkader Chouaih ◽  
Salem Yahiaoui ◽  
Nadia Benhalima ◽  
Manel Boulakoud ◽  
Rachida Rahmani ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Organic Semiconductor ◽  
Density Functional ◽  
Energy Gap ◽  
Three Dimensional ◽  
Basis Set ◽  
X Ray Diffraction ◽  
Hybrid Functional ◽  
X Ray ◽  
Lowest Unoccupied Molecular Orbital

The electronic and structural properties of thiazolic ring derivatives were studied using density functional theory (DFT) and X-ray diffraction in terms of their application as organic semiconductor materials in photovoltaic devices. The B3LYP hybrid functional in combination with Pople type 6-31G(d) basis set with a polarization function was used in order to determine the optimized geometries and the electronic properties of the ground state, while transition energies and excited state properties were obtained from DFT with B3LYP/6-31G(d) calculation. The investigation of thiazolic derivatives formed by the arrangement of several monomeric units revealed that three-dimensional (3D) conjugated architectures present the best geometric and electronic characteristics for use as an organic semiconductor material. The highest occupied molecular orbital (HOMO) . lowest unoccupied molecular orbital (LUMO) energy gap was decreased in 3D structures that extend the absorption spectrum toward longer wavelengths, revealing a feasible intramolecular charge transfer process in these systems. All calculations in this work were performed using the Gaussian 03 W software package.

scholarly journals Growth, Crystal Structure, Hirshfeld Surface Analysis, DFT Studies, Physicochemical Characterization And Cytotoxicity Assays of Novel Organic Triphosphate

2021 ◽  
Author(s):  
Yathreb Oueslati ◽  
Sevgi Kansız ◽  
Necmi Dege ◽  
Cristina de la Torre Paredes ◽  
Antoni Llopis Lorente ◽  
...  
Keyword(s):  
Density Functional ◽  
Three Dimensional ◽  
Physicochemical Characterization ◽  
Basis Set ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Hybrid Compound ◽  
X Ray ◽  
Molecular Arrangement ◽  
Chemical Procedure

Abstract A novel interesting organic-inorganic hybrid compound, named (1-phenylpiperazinium) trihydrogen triphosphate, with the formula (C10H15N2)2H3P3O10 has been obtained by low speed of evaporation at room temperature after using the ion exchange chemical procedure. To carry out a detailed crystallographic structure analysis, single-crystal X-ray diffraction has been reported. In the molecular arrangement, the different entities are held together through N-H…O, O-H…O and C-H…O hydrogen bonds, building up a three dimensional packing. Powder X-ray diffraction analysis is acquired to confirm the purity of the product. The nature and the proportion of intermolecular interactions were investigated by Hirshfeld surfaces analysis. In order to support the experimental results, a density functional theory (DFT) calculation were performed, using the Becke-3-Parameter-Lee-Yang-Parr (B3LYP) function with LANL2DZ basis set, and the data indicate the much agreement between the experimental and the theoretical results. Thus, the physicochemical properties were studied employing a variety of techniques (FT-IR, NMR, UV-Visible and photoluminescence). To get an insight of the possible employment of the present material in biology, cell viability assays were performed.

Surface-grafted lanthanoid complexes of the tungstosilicate polyanion [SiW12O40]4−: a synthetic, structural and computational investigation

2018 ◽  
Vol 74 (11) ◽  
pp. 1300-1309 ◽  
Author(s):  
Shadi Derakhshanrad ◽  
Masoud Mirzaei ◽  
Atefeh Najafi ◽  
Chris Ritchie ◽  
Antonio Bauzá ◽  
...  
Keyword(s):  
Dicarboxylic Acid ◽  
Intermolecular Interactions ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Three Dimensional ◽  
Computational Investigation ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Supramolecular Architectures

As an extension of our continued interest in the preparation of inorganic–organic hybrids, we report the successful hydrothermal synthesis of sodium tris[triaqua(μ-1,10-phenanthroline-2,9-dicarboxylato)dysprosium(III)] silicododecatungstate dodecahydrate, {[DyNa(C14H6N2O4)3(H2O)9(SiW12O40)]·12H2O}nor Na[Dy(PDA)(H2O)3]3[SiW12O40]·12H2O (1), and sodium aqua tris[tetraaqua(μ-4-hydroxypyridine-2,6-dicarboxylato)praseodymium(III)] silicododecatungstate dodecahydrate, {[NaPr(C7H3NO5)3(H2O)13(SiW12O40)]·12H2O}nor Na(H2O)[Pr(pydc-OH)(H2O)4]3[SiW12O40]·12H2O (2) (in which H2PDA is 1,10-phenanthroline-2,9-dicarboxylic acid and H2pydc-OH is 4-hydroxypyridine-2,6-dicarboxylic acid or chelidamic acid). Both compounds have been characterized using elemental analysis, IR spectroscopy and X-ray diffraction methods. Structural characterization by single-crystal X-ray diffraction reveals that these compounds consist of [SiW12O40]4−Keggin-type polyoxometalates (POMs), where a single {W3O13} triad is decorated with a trinuclear Ln complex. Moreover, the decorated polyanions are involved in a series of intermolecular interactions, such as hydrogen bonds and anion–π interactions, resulting in three-dimensional supramolecular architectures. Density functional theory (DFT) studies were conducted to support these intermolecular interactions in both1and2, and have been rationalized using molecular electrostatic potential (MEP) surface calculations.

scholarly journals Theoretical Investigations of a BN Polymorph with sp2 + sp3 Hybridizations

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1574
Author(s):  
Xinhai Yu ◽  
Riguge Su ◽  
Bei He ◽  
Binchang Ma
Keyword(s):  
Density Functional ◽  
Mechanical Anisotropy ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Theoretical Investigations ◽  
M Phase ◽  
The Difference ◽  
The Stability ◽  
Xrd Patterns

The crystal structure, mechanical anisotropy, elastic properties and electronic characteristics, as well as the stability, of P4/m BN are predicted by means of density functional theory. In this work, BN in the P4/m phase demonstrates mechanical and dynamical stability. Compared with the values of bulk B, E and G in the P4/m phase, the B of BN in the P4/m phase is greater than that of dz4 BN, while the G and E of P4/m BN are greater than those of Pnc2 BN and dz4 BN. The ratio of the bulk-to-shear modulus for P4/m BN is less than 1.75 and dz4 BN, dz2 BN and lzlz2 BN, indicating that P4/m BN is more brittle than dz4 BN, dz2 BN and lzlz2 BN. P4/m BN exhibits stronger mechanical anisotropy in G and E than Pbca BN, P42/mnm BN and Pm-3m BN but much weaker mechanical anisotropy than P4/mbm BN, B7N7, B11N11 and B15N15. In addition, P4/m BN is a quasi-direct bandgap semiconductor, and the difference between the direct and the indirect bandgap is 0.008 eV. In order to obtain further characteristics of P4/m BN for future synthetic verification, the X-ray diffraction (XRD) patterns for P4/m BN are also calculated. Given its properties, P4/m BN is a good candidate for photoelectric devices.

scholarly journals Mechanochemical Syntheses of Isostructural Luminescent Cocrystals of 9-Anthracenecarboxylic Acid with two Dipyridines Coformers

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 889
Author(s):  
Torvid Feiler ◽  
Biswajit Bhattacharya ◽  
Adam A. L. Michalchuk ◽  
Vincent Schröder ◽  
Emil List-Kratochvil ◽  
...  
Keyword(s):  
Solid State ◽  
Crystal Engineering ◽  
Density Functional ◽  
Photophysical Properties ◽  
Three Dimensional ◽  
Luminescent Materials ◽  
Primary Role ◽  
X Ray Diffraction ◽  
X Ray ◽  
Interpenetrated Structure

Tuning and controlling the solid-state photophysical properties of organic luminophore are very important to develop next-generation organic luminescent materials. With the aim of discovering new functional luminescent materials, new cocrystals of 9-anthracene carboxylic acid (ACA) were prepared with two different dipyridine coformers: 1,2-bis(4-pyridyl)ethylene and 1,2-bis(4-pyridyl)ethane. The cocrystals were successfully obtained by both mechanochemical approaches and conventional solvent crystallization. The newly obtained crystalline solids were characterized thoroughly using a combination of single crystal X-ray diffraction, powder X-ray diffraction, Fourier-transform infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. Structural analysis revealed that the cocrystals are isostructural, exhibiting two-fold interpenetrated hydrogen bonded networks. While the O–H···N hydrogen bonds adopts a primary role in the stabilization of the cocrystal phases, the C–H···O hydrogen bonding interactions appear to play a significant role in guiding the three-dimensional assembly. Both π···π and C–H···π interactions assist in stabilizing the interpenetrated structure. The photoluminescence properties of both the starting materials and cocrystals were examined in their solid states. All the cocrystals display tunable photophysical properties as compared to pure ACA. Density functional theory simulations suggest that the modified optical properties result from charge transfers between the ACA and coformer molecules in each case. This study demonstrates the potential of crystal engineering to design solid-state luminescence switching materials through cocrystallization.

Chemistry of transition-metal complexes containing functionalized phosphines: synthesis and structural analysis of rhodium(I) complexes containing allyl and cyanoalkylphosphines

2020 ◽  
Vol 76 (9) ◽  
pp. 932-946
Author(s):  
Reinaldo Atencio ◽  
Gustavo Chacón ◽  
Lisbeth Mendoza ◽  
Teresa González ◽  
Julia Bruno-Colmenarez ◽  
...  
Keyword(s):  
Density Functional ◽  
Three Dimensional ◽  
Coupling Constants ◽  
Molecular Surface ◽  
Planar Geometry ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Conformational Preferences ◽  
Square Planar

A series of related acetylacetonate–carbonyl–rhodium compounds substituted by functionalized phosphines has been prepared in good to excellent yields by the reaction of [Rh(acac)(CO)2] (acac is acetylacetonate) with the corresponding allyl-, cyanomethyl- or cyanoethyl-substituted phosphines. All compounds were fully characterized by 31P, 1H, 13C NMR and IR spectroscopy. The X-ray structures of (acetylacetonato-κ2 O,O′)(tert-butylphosphanedicarbonitrile-κP)carbonylrhodium(I), [Rh(C5H7O2)(CO)(C8H13N2)] or [Rh(acac)(CO)(tBuP(CH2CN)2}] (2b), (acetylacetonato-κ2 O,O′)carbonyl[3-(diphenylphosphanyl)propanenitrile-κP]rhodium(I), [Rh(C5H7O2)(C15H14N)(CO)] or [Rh(acac)(CO){Ph2P(CH2CH2CN)}] (2h), and (acetylacetonato-κ2 O,O′)carbonyl[3-(di-tert-butylphosphanyl)propanenitrile-κP]rhodium(I), [Rh(C5H7O2)(C11H22N)(CO)] or [Rh(acac)(CO){tBu2P(CH2CH2CN)}] (2i), showed a square-planar geometry around the Rh atom with a significant trans influence over the acetylacetonate moiety, evidenced by long Rh—O bond lengths as expected for poor π-acceptor phosphines. The Rh—P distances displayed an inverse linear dependence with the coupling constants J P-Rh and the IR ν(C[triple-bond]O) bands, which accounts for the Rh—P electronic bonding feature (poor π-acceptors) of these complexes. A combined study from density functional theory (DFT) calculations and an evaluation of the intramolecular H...Rh contacts from X-ray diffraction data allowed a comparison of the conformational preferences of these complexes in the solid state versus the isolated compounds in the gas phase. For 2b, 2h and 2i, an energy-framework study evidenced that the crystal structures are mainly governed by dispersive energy. In fact, strong pairwise molecular dispersive interactions are responsible for the columnar arrangement observed in these complexes. A Hirshfeld surface analysis employing three-dimensional molecular surface contours and two-dimensional fingerprint plots indicated that the structures are stabilized by H...H, C...H, H...O, H...N and H...Rh intermolecular interactions.

On the transferability of QTAIMC descriptors derived from X-ray diffraction data and DFT calculations: substituted hydropyrimidine derivatives

2011 ◽  
Vol 67 (5) ◽  
pp. 425-436 ◽  
Author(s):  
A. A. Rykounov ◽  
A. I. Stash ◽  
V. V. Zhurov ◽  
E. A. Zhurova ◽  
A. A. Pinkerton ◽  
...  
Keyword(s):  
Electron Density ◽  
Density Functional ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Covalent Bonds ◽  
Functional Theory ◽  
X Ray ◽  
Biginelli Compounds ◽  
Empirical Corrections

The combined study of electron-density features in three substituted hydropyrimidines of the Biginelli compound family has been fulfilled. Results of the low-temperature X-ray diffraction measurements and density functional theory (DFT) B3LYP/6-311++G** calculations of these compounds are described. The experimentally derived atomic and bonding characteristics determined within the quantum-topological theory of atoms in molecules and crystals (QTAIMC) were demonstrated to be fully transferable within chemically similar structures such as the Biginelli compounds. However, for certain covalent bonds they differ significantly from the theoretical results because of insufficient flexibility of the atom-centered multipole electron density model. It was concluded that currently analysis of the theoretical electron density provides a more reliable basis for the determination of the transferability of QTAIMC descriptors for molecular structures. Empirical corrections making the experimentally derived QTAIMC bond descriptors more transferable are proposed.

The alkaline earth-palladium-germanides Sr3Pd4Ge4 and BaPdGe

2018 ◽  
Vol 73 (3-4) ◽  
pp. 243-250 ◽  
Author(s):  
Sebastian Stein ◽  
Samir F. Matar ◽  
Kai Heinz Schmolke ◽  
Jutta Kösters ◽  
Rainer Pöttgen
Keyword(s):  
Density Functional ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Space Group ◽  
X Ray ◽  
Overlap Population ◽  
The Density Functional Theory ◽  
Structure Investigations

AbstractThe germanides Sr3Pd4Ge4and BaPdGe were obtained from high-temperature reactions in sealed niobium ampoules and their structures have been determined from single-crystal X-ray diffraction data:a=444.2(1),b=438.1(1),c=2472.2(7) pm, space groupImmm, U3Ni4Si4type,wR2=0.0471, 576 unique reflections, 25 parameters for Sr3Pd4Ge4anda=677.09(8), space groupP213, LaIrSi type,wR2=0.0322, 409 unique reflections, nine parameters for BaPdGe. Both germanides have pronounced three-dimensional [Pd4Ge4]δ−and [PdGe]δ−polyanionic networks with Pd–Ge bonding interactions. This is confirmed by the density functional theory (DFT)-based electronic structure investigations, the trends of charge transfer and crystal orbital overlap population (COOP) analyses.

Investigation of Inorganic-Intercalated Vermiculite by X-Ray Diffraction

2010 ◽  
Vol 177 ◽  
pp. 602-605 ◽  
Author(s):  
Chun Feng Wang ◽  
Hua Zhi Gu ◽  
Fei Zhou
Keyword(s):  
Interlayer Spacing ◽  
Peak Position ◽  
Diffraction Peak ◽  
Layer Silicate ◽  
Inorganic Component ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanometer Particles ◽  
Xrd Patterns ◽  
Xrd Method

Vermiculite is a layer silicate with an interlayer spacing about 1-2nm. The interlayer of inorganic-pillared vermiculite inlaid with a large amount of nanometer particles and micropores. It isn’t suitable to characterize the structure of inorganic-pillared vermiculite by SEM and TEM. In this paper, the microstructure of inorganic-pillared vermiculites obtained at different steps is characterized by XRD method. The interlayer spacing of inorganic-pillared vermiculite is obtained by analyzing the diffraction peak position and intensity in XRD patterns. The results show that the inorganic component is successfully inserted into the interlayer of vermiculite. Pillared vermiculite show higher intrinsic thermal stability and intensity than crude vermiculite.

X-ray diffraction and density functional theory studies of R(Fe0.5Co0.5)O3 (R = Pr, Nd, Sm, Eu, Gd)

2016 ◽  
Vol 31 (4) ◽  
pp. 259-266 ◽  
Author(s):  
W. Wong-Ng ◽  
G. Liu ◽  
I. Levin ◽  
I. Williamson ◽  
P. Ackerman ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Transmission Electron ◽  
Bond Strain ◽  
Xrd Patterns

The structure of a series of lanthanide iron cobalt perovskite oxides, R(Fe0.5Co0.5)O3 (R = Pr, Nd, Sm, Eu, and Gd), have been investigated. The space group of these compounds was confirmed to be orthorhombic Pnma (No. 62), Z = 4. From Pr to Gd, the lattice parameter a varies from 5.466 35(13) Å to 5.507 10(13) Å, b from 7.7018(2) to 7.561 75(13) Å, c from 5.443 38(10) to 5.292 00(8) Å, and unit-cell volume V from 229.170(9) Å3 to 220.376(9) Å3, respectively. While the trend of V follows the trend of the lanthanide contraction, the lattice parameter “a” increases as the ionic radius r(R3+) decreases. X-ray diffraction (XRD) and transmission electron microscopy confirm that Fe and Co are disordered over the octahedral sites. The structure distortion of these compounds is evidenced in the tilt angles θ, ϕ, and ω, which represent rotations of an octahedron about the pseudocubic perovskite [110]p, [001]p, and [111]p axes. All three tilt angles increase across the lanthanide series (for R = Pr to R = Gd: θ increases from 12.3° to 15.2°, ϕ from 7.5° to 15.8°, and ω from 14.4° to 21.7°), indicating a greater octahedral distortion as r(R3+) decreases. The bond valence sum for the sixfold (Fe/Co) site and the eightfold R site of R(Fe0.5Co0.5)O3 reveal no significant bond strain. Density Functional Theory calculations for Pr(Fe0.5Co0.5)O3 support the disorder of Fe and Co and suggest that this compound to be a narrow band gap semiconductor. XRD patterns of the R(Fe0.5Co0.5)O3 samples were submitted to the Powder Diffraction File.

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