Low-pressure metastable phase of single-bonded polymeric nitrogen from a helical structure motif and first-principles calculations

2007 ◽  
Vol 75 (14) ◽  
Author(s):  
F. Zahariev ◽  
J. Hooper ◽  
S. Alavi ◽  
F. Zhang ◽  
T. K. Woo
Keyword(s):  
First Principles ◽  
Metastable Phase ◽  
Helical Structure ◽  
Low Pressure ◽  
First Principles Calculations ◽  
Polymeric Nitrogen

Low-pressure superconductivity in lithium-doped methane predicted by first principles

2020 ◽  
pp. 2150032
Author(s):  
Ning Lu ◽  
Yu-Long Hai ◽  
Hai-Yan Lv ◽  
Wen-Jie Li ◽  
Chun-Lei Yang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
High Temperature ◽  
Crystal Field ◽  
First Principles ◽  
Pressure Range ◽  
High Temperature Superconductor ◽  
Low Pressure ◽  
First Principles Calculations ◽  
A Charge ◽  
Low Pressures

To explore the high-temperature superconductor at low pressures, we have investigated the crystal structures, electronic properties, and possible superconductivity in the case of methane (CH4) doped by lithium in the pressure range of [Formula: see text][Formula: see text]GPa, based on the first-principles calculations. The results show that Li-intercalated CH4 (Lix(CH4)[Formula: see text]) can realize metallization and superconductivity at low pressures, even 5[Formula: see text]GPa. We find that there is a charge transfer between Li and CH4, but the metallization is driven by the change of crystal field induce by doping instead of charge transfer. The critical temperture is predicted from 3.8[Formula: see text]K at 5[Formula: see text]GPa for LiCH4 to 12.1[Formula: see text]K at 100[Formula: see text]GPa for Li(CH4)4. The low-pressure superconductivity of Lix(CH4)[Formula: see text] can be further optimized by adjusting component and pressure.

Construction of a series of zero-dimensional/one-dimensional crystalline Zn–S clusters – effect of the character of bridging organic ligands on structural diversity

2015 ◽  
Vol 2 (2) ◽  
pp. 164-169 ◽  
Author(s):  
Xianghua Zeng ◽  
Xiaojing Yao ◽  
Junyong Zhang ◽  
Qi Zhang ◽  
Wenqian Wu ◽  
...  
Keyword(s):  
First Principles ◽  
Structural Diversity ◽  
Helical Structure ◽  
Organic Ligands ◽  
First Principles Calculations ◽  
One Dimensional

A series of Zn–S clusters have been synthesised and a very rare 1D helical structure was illustrated by first-principles calculations.

Nuclear dynamics in the metastable phase of the solid acid caesium hydrogen sulfate

2015 ◽  
Vol 17 (46) ◽  
pp. 31287-31296 ◽  
Author(s):  
Maciej Krzystyniak ◽  
Kacper Drużbicki ◽  
Felix Fernandez-Alonso
Keyword(s):  
First Principles ◽  
Solid Acid ◽  
Metastable Phase ◽  
Neutron Spectroscopy ◽  
Hydrogen Sulfate ◽  
First Principles Calculations ◽  
Nuclear Dynamics

Neutron spectroscopy and first-principles calculations unveil the quantum character of atomic motions in the solid acid CsHSO4.

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption

To Bend or Not to Bend, the Dilemma of Multiple Bonds

2019 ◽  
Author(s):  
Michele Pizzocchero ◽  
Matteo Bonfanti ◽  
Rocco Martinazzo
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Main Group ◽  
First Principles Calculations ◽  
Group 14 ◽  
Multiple Bonds ◽  
Main Group Elements ◽  
Structural Distortions

The manuscript addresses the issue of the structural distortions occurring at multiple bonds between high main group elements, focusing on group 14. These distortions are known as trans-bending in silenes, disilenes and higher group analogues, and buckling in 2D materials likes silicene and germanene. A simple but correlated \sigma + \pi model is developed and validated with first-principles calculations, and used to explain the different behaviour of second- and higher- row elements.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

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