scholarly journals Facile Electron Transfer to CO2 during Adsorption at the Metal | Solution Interface

2019 ◽  
Author(s):  
Joseph Gauthier ◽  
Meredith Fields ◽  
Michal Bajdich ◽  
Leanne D. Chen ◽  
Robert B. Sandberg ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Adsorption Process ◽  
Density Functional Theory Calculations ◽  
High Rate ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Solution Interface

<i>We estimate the rate of electron transfer to CO2 at the Au (211)|water interface during adsorption in an electrochemical environment under reducing potentials. Based on density functional theory calculations at the generalized gradient approximation and hybrid levels of theory, we find electron transfer to adsorbed *CO2 to be very facile. This high rate of transfer is estimated by the energy distribution of the adsorbate-induced density of states as well as from the interaction between diabatic states representing neutral and negatively charged CO2. Up to 0.62 electrons are transferred to CO2, and this charge adiabatically increases with the bending angle to a lower limit of 137°. We conclude that this rate of electron transfer is extremely fast compared to the timescale of the nuclear degrees of freedom, that is, the adsorption process.</i><br>

scholarly journals Electron Transfer to CO2 during Adsorption at the Metal | Solution Interface

2019 ◽  
Author(s):  
Michal Bajdich ◽  
Meredith Fields ◽  
Leanne D. Chen ◽  
Robert B. Sandberg ◽  
Karen Chan ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Adsorption Process ◽  
Density Functional Theory Calculations ◽  
High Rate ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Solution Interface

<i>We estimate the rate of electron transfer to CO<sub>2</sub> at the Au(211)|water interface during adsorption in an electrochemical environment under negative potentials. Based on density functional theory calculations at the generalized gradient approximation, hybrid, and GW levels of theory, we find electron transfer to adsorbed *CO<sub>2</sub> to be very facile. This high rate of transfer is estimated by the energy distribution of the adsorbate-induced density of states as well as from the interaction between diabatic states representing neutral and negatively charged CO<sub>2</sub>. Up to 0.54 electrons is transferred to CO<sub>2</sub>, and this charge adiabatically increases with the bending angle to a lower limit of 140°. We conclude that this rate of electron transfer is extremely fast compared to the timescale of the nuclear degrees of freedom, that is, the adsorption process</i><br>

scholarly journals Facile Electron Transfer to CO2 during Adsorption at the Metal | Solution Interface

2019 ◽  
Author(s):  
Joseph Gauthier ◽  
Meredith Fields ◽  
Michal Bajdich ◽  
Leanne D. Chen ◽  
Robert B. Sandberg ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Adsorption Process ◽  
Density Functional Theory Calculations ◽  
High Rate ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Solution Interface

<i>We estimate the rate of electron transfer to CO2 at the Au (211)|water interface during adsorption in an electrochemical environment under reducing potentials. Based on density functional theory calculations at the generalized gradient approximation and hybrid levels of theory, we find electron transfer to adsorbed *CO2 to be very facile. This high rate of transfer is estimated by the energy distribution of the adsorbate-induced density of states as well as from the interaction between diabatic states representing neutral and negatively charged CO2. Up to 0.62 electrons are transferred to CO2, and this charge adiabatically increases with the bending angle to a lower limit of 137°. We conclude that this rate of electron transfer is extremely fast compared to the timescale of the nuclear degrees of freedom, that is, the adsorption process.</i><br>

Behavior of Si Interstitials and Boron-Interstitial Pairs at the Si/SiO2 Interface

2004 ◽  
Vol 810 ◽  
Author(s):  
Taras A. Kirichenko ◽  
Decai Yu ◽  
Sanjay K. Banerjee ◽  
Gyeong S. Hwang
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Valuable Insight ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Diffusion Behavior ◽  
Generalized Gradient Approximation ◽  
And Diffusion ◽  
Insight Into

ABSTRACTUsing density functional theory calculations within the generalized gradient approximation, we have investigated the structure, energetics, bonding, and diffusion behavior of Si interstitials and boron-interstitial pairs at the Si/SiO2 interface. We find that interstitials are significantly stabilized at the Si/SiO2 interface and prefer to reside on the SiO2 side rather than the Si side. Due to the interstitial stabilization, boron-interstitial pairs are likely to be easily dissociated in the vicinity of the Si/SiO2 interface. This study provides valuable insight into interstitial annihilation and boron precipitation at the interface.

Dissociation of dinitrogen on iron clusters: A detailed study of the Fe16 + N2 case.

2020 ◽  
Author(s):  
Bole Chen ◽  
Gennady L. Gutsev ◽  
Weiguo Sun ◽  
Xiao-Yu Kuang ◽  
Cheng Lu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Basis Set ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Iron Clusters ◽  
Generalized Gradient Approximation

The coalescence of two Fe8N as well as the structure of the Fe16N2 cluster were studied using density functional theory with the generalized gradient approximation and a basis set of...

scholarly journals Spectroscopic evidence for direct flavin-flavin contact in a bifurcating electron transfer flavoprotein

2020 ◽  
Vol 295 (36) ◽  
pp. 12618-12634
Author(s):  
H. Diessel Duan ◽  
Nishya Mohamed-Raseek ◽  
Anne-Frances Miller
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Protein Denaturation ◽  
Rhodopseudomonas Palustris ◽  
Density Functional Theory Calculations ◽  
Site Directed Mutagenesis ◽  
Functional Theory ◽  
Electron Transfer Flavoprotein ◽  
Midpoint Potential ◽  
Ct Complex

A remarkable charge transfer (CT) band is described in the bifurcating electron transfer flavoprotein (Bf-ETF) from Rhodopseudomonas palustris (RpaETF). RpaETF contains two FADs that play contrasting roles in electron bifurcation. The Bf-FAD accepts electrons pairwise from NADH, directs one to a lower-reduction midpoint potential (E°) carrier, and the other to the higher-E° electron transfer FAD (ET-FAD). Previous work noted that a CT band at 726 nm formed when ET-FAD was reduced and Bf-FAD was oxidized, suggesting that both flavins participate. However, existing crystal structures place them too far apart to interact directly. We present biochemical experiments addressing this conundrum and elucidating the nature of this CT species. We observed that RpaETF missing either FAD lacked the 726 nm band. Site-directed mutagenesis near either FAD produced altered yields of the CT species, supporting involvement of both flavins. The residue substitutions did not alter the absorption maximum of the signal, ruling out contributions from residue orbitals. Instead, we propose that the residue identities modulate the population of a protein conformation that brings the ET-flavin and Bf-flavin into direct contact, explaining the 726 nm band based on a CT complex of reduced ET-FAD and oxidized Bf-FAD. This is corroborated by persistence of the 726 nm species during gentle protein denaturation and simple density functional theory calculations of flavin dimers. Although such a CT complex has been demonstrated for free flavins, this is the first observation of such, to our knowledge, in an enzyme. Thus, Bf-ETFs may optimize electron transfer efficiency by enabling direct flavin-flavin contact.

An Investigation of Half-Metallic Ferromagnets Behavior in Hg2CuTi-Type Heusler Alloy Ti2FeAl by Using GGA

2012 ◽  
Vol 535-537 ◽  
pp. 1291-1294 ◽  
Author(s):  
Xiu De Yang ◽  
Bo Wu ◽  
Song Zhang
Keyword(s):  
Density Functional Theory ◽  
Heusler Alloy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Indirect Exchange ◽  
The Density Functional Theory ◽  
Direct Hybridization

By using generalized gradient approximation (GGA) scheme within the density functional theory (DFT), the electronic and magnetic properties of Hg2CuTi-type Heusler alloy Ti2FeAl were investigated. The results reveal that a 100% spin polarization appears at Fermi level (εF) in Ti2FeAl, and is maintained during lattice range of 5.1Å~6.2Å. Ti2FeAl is one of stable Half-Metallic Ferromagnets (HMF) with a spin-minority gap of 0.5 eV at εF and total magnetic moment of 1μB per unit cell. Our studies also indicate that the competition between RKKY-type indirect exchange and direct hybridization of d-electronic atoms plays a dominating role in determining the magnetism.

Thermoelectric Transport Properties of SrTiO3 Doped with Pm

2018 ◽  
Vol 280 ◽  
pp. 3-8 ◽  
Author(s):  
A. A. Adewale ◽  
Abdullah Chik ◽  
R. Mohd Zaki ◽  
F. Che Pa ◽  
Yeoh Chow Keat ◽  
...  
Keyword(s):  
Transport Properties ◽  
Figure Of Merit ◽  
Density Functional ◽  
Generalized Gradient ◽  
Thermoelectric Figure ◽  
Functional Theory ◽  
Thermoelectric Transport ◽  
Generalized Gradient Approximation ◽  
High Contribution ◽  
Thermoelectric Transport Properties

Thermoelectric properties of SrTiO3doped with 8%Pm at Sr site were investigated using density functional theory and generalized gradient approximation. The transport properties were calculated based on BoltzTraP code at temperature range 300-1200K. In electronic properties study Fermi level were shifted to conduction band region due to high contribution 4f orbital in Pm. Present study thermoelectric figure of merit ZT result was 0.395 at 300K and 0.638 at 1200K. This shows a considerably good value of ZT for SrTiO3as n-type oxide. Compared to previous work, ZT were at the range of 0.21 - 0.37 for temperature of 300-1000K in Pr, La, Ta and Ho.

scholarly journals Structural, Electronic, and Magnetic Properties of Mn4N Perovskite: Density Functional Theory Calculations and Monte Carlo Study

2019 ◽  
Vol 33 (5) ◽  
pp. 1507-1512 ◽  
Author(s):  
A. Azouaoui ◽  
M. El Haoua ◽  
S. Salmi ◽  
A. El Grini ◽  
N. Benzakour ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Monte Carlo ◽  
Magnetic Properties ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Generalized Gradient ◽  
Critical Temperatures ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Electronic And Magnetic Properties

AbstractIn this paper, we have studied the structural, electronic, and magnetic properties of the cubic perovskite system Mn4N using the first principles calculations based on density functional theory (DFT) with the generalized gradient approximation (GGA). The obtained data from DFT calculations are used as input data in Monte Carlo simulation with a mixed spin-5/2 and 1 Ising model to calculate the magnetic properties of this compound, such as the total, partial thermal magnetization, and the critical temperatures (TC). The obtained results show that Mn4N has a ferrimagnetic structure with two different sites of Mn in the lattice and presents a metallic behavior. The obtained TC is in good agreement with experimental results.

scholarly journals Thermodynamics of Uranium Tri-Iodide from Density-Functional Theory

2020 ◽  
Vol 10 (11) ◽  
pp. 3914
Author(s):  
Per Söderlind ◽  
Aurélien Perron ◽  
Emily E. Moore ◽  
Alexander Landa ◽  
Tae Wook Heo
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Heat Capacity ◽  
Density Functional ◽  
Thermodynamic Assessment ◽  
Harmonic Approximation ◽  
Metallic System ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation

Density-functional theory (DFT) is employed to investigate the thermodynamic and ground-state properties of bulk uranium tri-iodide, UI3. The theory is fully relativistic and electron correlations, beyond the DFT and generalized gradient approximation, are addressed with orbital polarization. The electronic structure indicates anti-ferromagnetism, in agreement with neutron diffraction, with band gaps and a non-metallic system. Furthermore, the formation energy, atomic volume, crystal structure, and heat capacity are calculated in reasonable agreement with experiments, whereas for the elastic constants experimental data are unavailable for comparison. The thermodynamical properties are modeled within a quasi-harmonic approximation and the heat capacity and Gibbs free energy as functions of temperature agree with available calculation of phase diagram (CALPHAD) thermodynamic assessment of the experimental data.

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