scholarly journals Hydration activity, crystal structural, and electronic properties studies of Ba-doped dicalcium silicate

2020 ◽  
Vol 9 (1) ◽  
pp. 1027-1033
Author(s):  
Lin Chi ◽  
Ailian Zhang ◽  
Zedong Qiu ◽  
Linchun Zhang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Dicalcium Silicate ◽  
Crystallographic Structure ◽  
Crystal Formation ◽  
First Principle ◽  
Functional Theory ◽  
Hydration Rate ◽  
Belite Cement

AbstractHigh belite cement has a wide application potential due to its low energy consumption, low CO2 emission, and excellent durability performance. Due to the low hydration rate and strength development at an early age, the activation of beta-dicalcium silicate (β-C2S) crystallographic structure is essential to improve the early strength of high belite cement. In this study, the β-C2S phase is activated by dissolving Ba2+ ions into the crystal lattice to improve the hydration rate. Unlike the traditional analysis methods of thermodynamics and dynamics theory, the first principle and density functional theory were applied to study the effect of Ba2+ ions on the activation of β-C2S, especially on the crystallographic structure, lattice parameters, and electronic structure change. The crystallographic structure of β-C2S can be activated by doping Ba atom and the crystal formation energy increases and the bandgap between VBM and CBM become narrow in the activated β-C2S crystallographic structure. Comparing the Ca2+ substitution in [CaO6] or [CaO8], the lattice deformation and hydraulic reactivity is more significant in Ba2-C2S and Ba22-C2S. The first principle and density functional theory explains the change of the electronic structure of the activated crystallographic structure and provides a theoretical basis for the purposeful design of material structures.

The Electronic Structure of Ga-Doped Hydrogen-Passivated Germanene: First Principle Study

2020 ◽  
Vol 833 ◽  
pp. 157-161
Author(s):  
Mauludi Ariesto Pamungkas ◽  
Husain ◽  
Achmad Kafi Shobirin ◽  
Tri Sugiono ◽  
Masruroh Masruroh
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Band Gap ◽  
Density Functional ◽  
Dft Calculation ◽  
First Principle ◽  
Hydrogen Passivation ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Hydrogenated Graphene

Germanene, which has the same structure as graphene, is an exciting novel 2D functionalized material that controls its band gap using functionalization. The effects of the Ga atom and hydrogen atoms on the structure of Ga-doped H-passivated germanene were investigated with a density functional theory (DFT) calculation. H-passivated germanene has a direct gap of 2.10 eV. Opening the band gap in the H-passivated germanene is due to transition from sp2 to sp3 orbital. Adsorption of the Ga adatom on H-site decrease the band gap to 1.38 eV. No interaction between Ga atoms and Hydrogen atoms was observed. Hence, their effects on the band structure of hydrogenated graphene were independent of each other. Our results suggest that hydrogen passivation combined with adsorption of the Ga adatoms could effectively control the band gap of germanene.

Doping effects on the geometric and electronic structure of tin clusters

2019 ◽  
Vol 21 (44) ◽  
pp. 24478-24488 ◽  
Author(s):  
Martin Gleditzsch ◽  
Marc Jäger ◽  
Lukáš F. Pašteka ◽  
Armin Shayeghi ◽  
Rolf Schäfer
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Beam Deflection ◽  
Functional Theory ◽  
Doping Effects ◽  
Depth Analysis ◽  
Trajectory Simulations

In depth analysis of doping effects on the geometric and electronic structure of tin clusters via electric beam deflection, numerical trajectory simulations and density functional theory.

scholarly journals Influence of Copper(I) Halides on the Reactivity of Aliphatic Carbodiimides

2020 ◽  
Vol 3 (1) ◽  
pp. 20
Author(s):  
Valentina Ferraro ◽  
Marco Bortoluzzi
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
General Formula ◽  
Electron Density ◽  
Density Functional ◽  
Functional Theory ◽  
Fukui Functions ◽  
Bond Lengths ◽  
Linear Complexes ◽  
Nitrogen Bond

The influence of copper(I) halides CuX (X = Cl, Br, I) on the electronic structure of N,N′-diisopropylcarbodiimide (DICDI) and N,N′-dicyclohexylcarbodiimide (DCC) was investigated by means of computational DFT (density functional theory) methods. The coordination of the considered carbodiimides occurs by one of the nitrogen atoms, with the formation of linear complexes having a general formula of [CuX(carbodiimide)]. Besides varying the carbon–nitrogen bond lengths, the thermodynamically favourable interaction with Cu(I) reduces the electron density on the carbodiimides and alters the energies of the (NCN)-centred, unoccupied orbitals. A small dependence of these effects on the choice of the halide was observable. The computed Fukui functions suggested negligible interaction of Cu(I) with incoming nucleophiles, and the reactivity of carbodiimides was altered by coordination mainly because of the increased electrophilicity of the {NCN} fragments.

Photophysical Properties of N-Methyl and N-Acetyl Substituted Alloxazine: A Theoretical Investigation

2021 ◽  
Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Photophysical Properties ◽  
Time Dependent ◽  
Functional Theory ◽  
Td Dft ◽  
Dependent Density

The electronic structure and photophysical properties of a series of N-Methyl and N-Acetyl substituted alloxazine (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...

Electronic Structure and Optical Properties of Non-Metals (N, F, P, Cl, S)-Doped Cubic NaTaO3 by Density Functional Theory

2009 ◽  
Vol 79-82 ◽  
pp. 1245-1248 ◽  
Author(s):  
Pei Lin Han ◽  
Xiao Jing Wang ◽  
Yan Hong Zhao ◽  
Chang He Tang
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Structure ◽  
Visible Light ◽  
Absorption Edge ◽  
Density Functional ◽  
Red Shift ◽  
Functional Theory ◽  
Photoactive Materials ◽  
Metal Doped

Electronic structure and optical properties of non-metals (N, S, F, P, Cl) -doped cubic NaTaO3 were investigated systematically by density functional theory (DFT). The results showed that the substitution of (N, S, P, Cl) for O in NaTaO3 was effective in narrowing the band-gap relative to the F-doped NaTaO3. The larger red shift of the absorption edge and the higher visible light absorption at about 520 nm were found for the (N and P)-doped NaTaO3. The excitation from the impurity states to the conduction band may account for the red shift of the absorption edge in an electron-deficiency non-metal doped NaTaO3. The obvious absorption in the visible light region for (N and P)-doped NaTaO3 provides an important guidance for the design and preparation of the visible light photoactive materials.

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