scholarly journals First-Principles Calculations and Electron Density Topological Analysis of Covellite (CuS)

2014 ◽  
Vol 118 (31) ◽  
pp. 5823-5831 ◽  
Author(s):  
A. Morales-García ◽  
Antonio Lenito Soares ◽  
Egon C. Dos Santos ◽  
Heitor A. de Abreu ◽  
Hélio A. Duarte
Keyword(s):  
Electron Density ◽  
First Principles ◽  
Topological Analysis ◽  
First Principles Calculations

Influence of doping on the electrochemical properties of anatase

2002 ◽  
Vol 756 ◽  
Author(s):  
Marina V. Koudriachova ◽  
Simon W. de Leeuw
Keyword(s):  
Phase Separation ◽  
Electrochemical Properties ◽  
Electron Density ◽  
First Principles ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Lithium Intercalation ◽  
First Principles Calculations ◽  
Voltage Profile ◽  
Li Content

The effect of substitution on the intercalation properties of anatase-structured titania has been investigated in first principles calculations. Ti4+-ions were substituted by Zr4+, Al3+ and Sc3+ respectively and O2- -ions by N3-. For each compound the open circuit voltage profile (OCV) was calculated and compared to anatase. Lithium intercalation proceeds as in pure anatase through a phase separation into a Li-rich and a Li-poor phase in all cases examined here. The Li-content of the phases depends on the nature of the dopant and its concentration. Substitution by N3--ions does not lead to lower potentials, whereas doping with trivalent Sc3+- and Al3+- ions decreases the intercalation voltage. Substitution by tetravalent Zr4+-ions within the range of solubility does not significantly affect the OCV of anatase. A correlation is observed between the predicted equilibrium voltage and the participation of the Ti4+-ions in accommodating the donated electron density upon lithiation.

FIRST-PRINCIPLES STUDY OF SnO2 (110)

1994 ◽  
Vol 01 (04) ◽  
pp. 491-494 ◽  
Author(s):  
I. MANASSIDIS ◽  
M.J. GILLAN
Keyword(s):  
Electron Density ◽  
First Principles ◽  
Perfect Crystal ◽  
First Principles Calculations ◽  
Oxygen Loss ◽  
First Principles Study ◽  
Gap States

Accurate first-principles calculations are used to study the relaxed stoichiometric and reduced SnO 2 (110) surfaces. The reliability of the calculations is supported by tests on the perfect crystal. Sizable atomic relaxations at both surfaces are found. Oxygen loss leaves electron density around surface Sn atoms, which can be regarded as being in the Sn 2+ state. There are gap states for the reduced but not for the stoichiometric surface.

First Principles Investigations on the Supramolecular Structure of 1,5-Diaminotetrazole

2012 ◽  
Vol 554-556 ◽  
pp. 65-69
Author(s):  
He Lin ◽  
Shun Guan Zhu ◽  
Lin Zhang ◽  
Xin Hua Peng ◽  
Hong Zhen Li
Keyword(s):  
Hydrogen Bonds ◽  
Electron Density ◽  
First Principles ◽  
Supramolecular Structure ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Intermolecular Hydrogen Bonds ◽  
Total Electron Density ◽  
Population Total ◽  
Total Electron

The supramolecular structure of 1,5-diaminotetrazole was investigated by first principles calculations, based on the plane-wave psedopotential method. The exchange-correlations potential was performed with the Perdew-Burke-Ernzerhof (PBE) functional of generalized gradient approximation (GGA). The Muliken population, total electron density and electron density difference were calculated. As a result, there are strong intramolecular and intermolecular hydrogen bonds among 1,5-diaminotetrazole molecules. The mainly reason for the formation of supramolecular structure of 1,5-diaminotetrazole is that the intermolecular hydrogen bonds of N(5)－H(5B)…N(4) and N(6)－H(6)…N(2).Moreover, chemical bond analysis showed that there are strong non-bond actions and the N(1)－N(5) bond seriously distorted was observed. The performance of 1,5-diaminotetrazole is quite related with the supramolecular structure.

Electron density of CaNi2Si2studied using synchrotron x-ray diffraction and first-principles calculations

2000 ◽  
Vol 12 (12) ◽  
pp. 2667-2679 ◽  
Author(s):  
G Gavoille ◽  
N K Hansen ◽  
R Welter ◽  
B Malaman ◽  
P Herzig ◽  
...  
Keyword(s):  
Electron Density ◽  
First Principles ◽  
First Principles Calculations ◽  
X Ray Diffraction ◽  
X Ray

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.

Sign in / Sign up

Export Citation Format

Share Document