Stability and metallization of solid oxygen at high pressure

2020 ◽  
Vol 22 (22) ◽  
pp. 12577-12583
Author(s):  
Sabri F. Elatresh ◽  
Stanimir A. Bonev
Keyword(s):  
High Pressure ◽  
First Principles ◽  
Pressure Range ◽  
Elevated Temperatures ◽  
Solid Oxygen

Using first principles theory, a metallic molecular phase of solid oxygen is determined to be thermodynamically stable at elevated temperatures in the pressure range between 50 and 100 GPa.

scholarly journals Novel structural phases and the properties of LaX (X = P, As) under high pressure: first-principles study

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 3058-3070
Author(s):  
Yu Zhou ◽  
Lan-Ting Shi ◽  
A-Kun Liang ◽  
Zhao-Yi Zeng ◽  
Xiang-Rong Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Pressure Range ◽  
Mechanical Stability ◽  
First Principles Study

The structures, phase transition, mechanical stability, electronic structures, and thermodynamic properties of lanthanide phosphates (LaP and LaAs) are studied in the pressure range of 0 to 100 GPa by first principles.

scholarly journals Mechanical properties and band structure of CdSe and CdTe nanostructures at high pressure - a first-principles study

2019 ◽  
Vol 13 (2) ◽  
pp. 124-131 ◽  
Author(s):  
Natarajan Kishore ◽  
Veerappan Nagarajan ◽  
Ramanathan Chandiramouli
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Shear Modulus ◽  
Band Structure ◽  
First Principles ◽  
Pressure Range ◽  
Uniaxial Pressure ◽  
First Principles Calculations ◽  
Zinc Blende ◽  
Cauchy Pressure

First-principles calculations for CdSe and CdTe nanostructures were carried out to study their mechanical properties and band structure under the uniaxial pressure range of 0 to 50GPa. It was presumed that the CdSe and CdTe nanostructures exist in the zinc-blende phase under high pressure. The mechanical properties, such as elastic constants, bulk modulus, shear modulus and Young?s modulus, were explored. Furthermore, Cauchy pressure, Poisson?s ratio and Pugh?s criterion were studied under high pressure for both CdSe and CdTe nanostructures, and the results show that they exhibit ductile property. The band structure studies of CdSe and CdTe were also investigated. The findings show that the mechanical properties and the band structures of CdSe and CdTe can be tailored with high pressure.

Pressure effects on mechanical and electronic properties of metallic C14 by first-principles calculation

2019 ◽  
Vol 33 (18) ◽  
pp. 1950193
Author(s):  
Yingjiao Zhou ◽  
Qun Wei ◽  
Bing Wei ◽  
Ruike Yang ◽  
Ke Cheng ◽  
...  
Keyword(s):  
High Pressure ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Pressure Range ◽  
Phonon Dispersion ◽  
Elastic Anisotropy ◽  
Acoustic Velocity ◽  
Pressure Effects ◽  
First Principles Calculation ◽  
First Principles Calculations

The elastic constants and phonon dispersion of metallic C[Formula: see text] are calculated by first-principles calculations. The results show that the metallic C[Formula: see text] is mechanically and dynamically stable under high pressure. The variations of G/B ratio, Poisson’s ratio, elastic anisotropy, acoustic velocity and Debye temperature at the pressure range from 0 GPa to 100 GPa are analyzed. The results reveal that by adjusting the pressures the elastic anisotropy and thermodynamic properties could be improved for better applicability.

First-principles study of the high-pressure behavior of crystalline benzoic acid

2017 ◽  
Vol 28 (10) ◽  
pp. 1750125 ◽  
Author(s):  
Limin Chen ◽  
Jie Qu ◽  
Zhikuo Tao ◽  
Qiyun Xie ◽  
Guozhi Xie ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Benzoic Acid ◽  
First Principles ◽  
Density Functional ◽  
Pressure Range ◽  
Structural Transformations ◽  
Absorption Properties ◽  
Functional Theory ◽  
Lattice Constants

In this work, a detailed study of the structural, electronic and optical absorption properties of crystalline benzoic acid in the pressure range of 0–300[Formula: see text]GPa is performed by density functional theory (DFT) calculations. We found that occur complex transformations in benzoic acid under compression occurs, by analyzing the variation tendencies of the lattice constants, bond lengths and bond angles under different pressures. In the pressure range 0–280[Formula: see text]GPa, repeated formations and disconnections of hydrogen bonds between H1(P1) atom and O1(P1), O2(P4-[Formula: see text]-[Formula: see text]-[Formula: see text]) atoms occur several times, and a new eight-atom ring (benzoic acid dimer) forms at 100[Formula: see text]GPa and 280[Formula: see text]GPa. Then, by analyzing the band gap and density of states (DOS) of benzoic acid, it is found that the crystal undergoes a phase transformation from insulator to semiconductor at 240[Formula: see text]GPa and it even becomes metal phase at 280[Formula: see text]GPa. In addition, the relatively high optical activity with the pressure increases of benzoic acid is seen from the absorption spectra, and three obvious structural transformations are also observed at 110, 240 and 290[Formula: see text]GPa, respectively.

scholarly journals Structural evolution of FeH4 under high pressure

RSC Advances ◽  
2017 ◽  
Vol 7 (21) ◽  
pp. 12570-12575 ◽  
Author(s):  
Fei Li ◽  
Dashuai Wang ◽  
Henan Du ◽  
Dan Zhou ◽  
Yanming Ma ◽  
...  
Keyword(s):  
High Pressure ◽  
First Principles ◽  
Pressure Range ◽  
Structural Evolution ◽  
Structural Search ◽  
Stable Structures

Here, we systematically investigated global energetically stable structures of FeH4 in the pressure range of 80–400 GPa using a first-principles structural search.

scholarly journals Ternary superconducting cophosphorus hydrides stabilized via lithium

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Ziji Shao ◽  
Defang Duan ◽  
Yanbin Ma ◽  
Hongyu Yu ◽  
Hao Song ◽  
...  
Keyword(s):  
High Pressure ◽  
First Principles ◽  
Structure Prediction ◽  
Pressure Range ◽  
High Temperature Superconductor ◽  
High Pressures ◽  
Experimental Studies ◽  
First Principles Calculations ◽  
Ternary Compounds ◽  
Stable Structures

Abstract Inspired by the diverse properties of sulfur hydrides and phosphorus hydrides, we combine first-principles calculations with structure prediction to search for stable structures of Li−P−H ternary compounds at high pressures with the aim of finding novel superconductors. It is found that phosphorus hydrides can be stabilized under pressure via additional doped lithium. Four stable stoichiometries LiPH3, LiPH4, LiPH6, and LiPH7 are uncovered in the pressure range of 100–300 GPa. Notably, we find an atomic LiPH6 with $$Pm\overline 3$$ P m 3 ¯ symmetry which is predicted to be a potential high-temperature superconductor with a Tc value of 150–167 K at 200 GPa and the Tc decreases upon compression. All the predicted stable ternary hydrides contain the P–H covalent frameworks with ionic lithium staying beside, but not for $$Pm\overline 3$$ P m 3 ¯ -LiPH6. We proposed a possible synthesis route for ternary lithium phosphorus hydrides: LiP + H2 → LiPHn, which could provide helpful and clear guidance to further experimental studies. Our work may provide some advice on further investigations on ternary superconductive hydrides at high pressure.

Role of dislocations in the bcc-hcp transition under high pressure: A first-principles approach in beryllium

2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Vanessa Riffet ◽  
Bernard Amadon ◽  
Nicolas Bruzy ◽  
Christophe Denoual
Keyword(s):  
High Pressure ◽  
First Principles
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