Structure, stability, and superconductivity of new Xe–H compounds under high pressure

2015 ◽  
Vol 143 (12) ◽  
pp. 124310 ◽  
Author(s):  
Xiaozhen Yan ◽  
Yangmei Chen ◽  
Xiaoyu Kuang ◽  
Shikai Xiang
Keyword(s):  
High Pressure ◽  
Structure Stability

scholarly journals Compression Behavior and Vibrational Properties of New Energetic Material LLM-105 Analyzed Using the Dispersion-Corrected Density Functional Theory

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6831
Author(s):  
Tianming Li ◽  
Junyu Fan ◽  
Zhuoran Wang ◽  
Hanhan Qi ◽  
Yan Su ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Uniaxial Compression ◽  
Density Functional ◽  
Structural Parameters ◽  
Energetic Material ◽  
Structure Stability ◽  
Vibrational Properties ◽  
Detailed Knowledge ◽  
Functional Theory

The 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is a newly energetic material with an excellent performance and low sensitivity and has attracted considerable attention. On the basis of the dispersion-corrected density functional theory (DFT-D), the high-pressure responses of vibrational properties, in conjunction with structural properties, are used to understand its intermolecular interactions and anisotropic properties under hydrostatic and uniaxial compressions. At ambient and pressure conditions, the DFT-D scheme could reasonably describe the structural parameters of LLM-105. The hydrogen bond network, resembling a parallelogram shape, links two adjacent molecules and contributes to the structure stability under hydrostatic compression. The anisotropy of LLM-105 is pronounced, especially for Raman spectra under uniaxial compression. Specifically, the red-shifts of modes are obtained for [100] and [010] compressions, which are caused by the pressure-induced enhance of the strength of the hydrogen bonds. Importantly, coupling modes and discontinuous Raman shifts are observed along [010] and [001] compressions, which are related to the intramolecular vibrational redistribution and possible structural transformations under uniaxial compressions. Overall, the detailed knowledge of the high-pressure responses of LLM-105 is established from the atomistic level. Uniaxial compression responses provide useful insights for realistic shock conditions.

Verification of Performance and Operating Characteristics of High Pressure Gas Injection Centrifugal Compressor

2015 ◽  
Author(s):  
Kazutoshi Yanagihara ◽  
Haruo Miura ◽  
Hideo Nishida ◽  
Kenji Tanaka ◽  
Naohiko Takahashi ◽  
...  
Keyword(s):  
High Pressure ◽  
Development Process ◽  
Oil And Gas ◽  
Material Selection ◽  
Aerodynamic Performance ◽  
Structure Stability ◽  
Operating Characteristics ◽  
High Pressure Compressor ◽  
Operational Tests ◽  
Pressure Compressor

The development process of a 70-MPa high pressure compressor for oil and gas applications is presented in this paper. Great attention was paid to any relevant technical challenges due to the high design pressures, such as the material selection, deformation casing structure, stability of the rotordynamics, and the aerodynamic performance. Among the technical considerations, some technical findings for the operational tests are proposed in this paper as well.

Synthesis and structure stability of Ba2CuO3+δ under high pressure

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542024 ◽  
Author(s):  
W. M. Li ◽  
Q. Q. Liu ◽  
Y. Liu ◽  
S. M. Feng ◽  
X. C. Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Equation Of State ◽  
Room Temperature ◽  
Text Structure ◽  
Structure Stability ◽  
Nominal Composition ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray

The [Formula: see text] sample with the nominal composition was synthesized. Powder X-ray diffraction (XRD) experiments confirm that it crystallizes in an orthorhombic structure with space group Immm. The synchrotron powder XRD results suggest that the crystal structure of [Formula: see text] keeps stable under pressure up to 34 GPa at room temperature with nearly isotropic compressibility. The equation of state for [Formula: see text] was obtained. The results offer opportunities to further synthesize and research [Formula: see text] superconductor with tetragonal [Formula: see text] structure.

Structural, elastic, electronic and thermodynamic properties of ZrB2 under high-pressure: First-principle study

2018 ◽  
Vol 32 (16) ◽  
pp. 1850200
Author(s):  
Guo Zhang ◽  
Yu-Xin Zhao ◽  
Jun Zhu ◽  
Yan-Jun Hao ◽  
Lin Zhang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Thermodynamic Properties ◽  
Dispersion Curve ◽  
Phonon Dispersion ◽  
Harmonic Approximation ◽  
Optimization Method ◽  
Hexagonal Structure ◽  
Phonon Dispersion Curve ◽  
Structure Stability

The structure of ZrB2 under high-pressure was predicted by Particle Swarm Optimization method (CALYPSO). We investigated the structure stability, phonon dispersion curve, elasticity, electronic structure and thermodynamic properties of ZrB2 under high-pressure and high-temperature via first-principles calculations. It maintained the hexagonal structure when the pressure lowers below 600 GPa at 0 K, which is confirmed by the calculated phonon dispersion curve. Studies indicate that the elastic modulus and Poisson’s ratio increase monotonically with pressure, as supported by some theoretical and experimental evidences. Calculated anisotropic factors demonstrate that compression and shear isotropy of ZrB2 weakens as the pressure increases. Using the quasi-harmonic approximation Debye model, the Debye temperature, sound velocity, expansion coefficient, thermal capacity under the high-temperature and pressure were also predicted.

scholarly journals Na2TiGeO5: Crystal structure stability at low temperature and high pressure

2008 ◽  
Vol 69 (4) ◽  
pp. 815-821 ◽  
Author(s):  
A. Waśkowska ◽  
L. Gerward ◽  
J. Staun Olsen ◽  
A. Sieradzki ◽  
W. Morgenroth
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Low Temperature ◽  
Structure Stability

Pressure transmitting medium-dependent structure stability of nanoanatase TiO2under high pressure

2014 ◽  
Vol 34 (2) ◽  
pp. 259-265 ◽  
Author(s):  
Qiming Wang ◽  
Duanwei He ◽  
Fang Peng ◽  
Li Lei ◽  
Lun Xiong ◽  
...  
Keyword(s):  
High Pressure ◽  
Structure Stability

Structure stability and mechanical properties of high-pressure die-cast Mg–Al–Ce–Y-based alloy

2012 ◽  
Vol 22 (2) ◽  
pp. 262-267 ◽  
Author(s):  
Jing-huai ZHANG ◽  
Shu-juan LIU ◽  
Zhe LENG ◽  
Mi-lin ZHANG ◽  
Jian MENG ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Structure Stability ◽  
Die Cast

The study of the structure stability of hexagonal Bi(PO4)(H2O)0.67 under high pressure

2017 ◽  
Vol 31 (25) ◽  
pp. 1745020 ◽  
Author(s):  
Jun Zhang ◽  
Zhen Yuan ◽  
Jian-Fa Zhao ◽  
Wen-Min Li ◽  
Ya-Ting Jia ◽  
...  
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Unit Cell Volume ◽  
Ambient Pressure ◽  
Structure Stability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Experimental Pressure ◽  
Text Unit

In this work, the structure stability of hexagonal Bi(PO[Formula: see text](H2O)[Formula: see text] has been investigated by high-pressure synchrotron X-ray diffraction measurements. The results show that the structure is stable within the pressure up to 18.3 GPa. The diffraction data are refined and the lattice constants [Formula: see text] and [Formula: see text] are determined, which is compressed by 6.3(7)% and 3.5(0)% within the experimental pressure, respectively. By fitting the pressure dependence of [Formula: see text] (unit cell volume divided by that at ambient pressure) with the second-order Birch equation of state, the bulk modulus [Formula: see text] is given to be about 87.1(0) GPa.

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