Microscopic evidence for the dissociation of water molecules on cleaved GaN(11̄00)

2018 ◽  
Vol 20 (2) ◽  
pp. 1261-1266 ◽  
Author(s):  
Shih-Yu Wu ◽  
Liang-Wei Lang ◽  
Pei-Yang Cai ◽  
Yun-Wen Chen ◽  
Yu-Ling Lai ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Water Molecules ◽  
Functional Theory ◽  
Microscopic Evidence

The dissociation of water molecules absorbed on a cleaved non-polar GaN(11̄00) surface was studied primarily with synchrotron-based photoemission spectra and density-functional-theory calculations.

scholarly journals Water dissociation and association on mirror twin boundaries in two-dimensional MoSe2: insights from density functional theory calculations

2021 ◽  
Author(s):  
Thomas Joseph ◽  
Mahdi Ghorbani-Asl ◽  
Matthias Batzill ◽  
Arkady V Krasheninnikov
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Point Defects ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Water Dissociation ◽  
Water Molecules ◽  
Two Dimensional ◽  
Functional Theory ◽  
Adsorption And Dissociation

The adsorption and dissociation of water molecules on two-dimensional transition metal dichalco- genides (TMDs) is expected to be dominated by point defects, such as vacancies, and edges. At the same...

scholarly journals Structures and reaction rates of the gaseous oxidation of SO<sub>2</sub> by an O<sub>3</sub><sup>−</sup>(H<sub>2</sub>O)<sub>0-5</sub> cluster – a density functional theory investigation

2012 ◽  
Vol 12 (8) ◽  
pp. 3639-3652 ◽  
Author(s):  
N. Bork ◽  
T. Kurtén ◽  
M. B. Enghoff ◽  
J. O. P. Pedersen ◽  
K. V. Mikkelsen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Atmospheric Chemistry ◽  
Density Functional ◽  
Transition States ◽  
Density Functional Theory Calculations ◽  
Reaction Rates ◽  
Water Molecules ◽  
Functional Theory ◽  
High Entropy ◽  
Collision Complexes

Abstract. Based on density functional theory calculations we present a study of the gaseous oxidation of SO2 to SO3 by an anionic O3−(H2O)n cluster, n = 0–5. The configurations of the most relevant reactants, transition states, and products are discussed and compared to previous findings. Two different classes of transition states have been identified. One class is characterised by strong networks of hydrogen bonds, very similar to the reactant complexes. The other class is characterised by sparser structures of hydration water and is stabilised by high entropy. At temperatures relevant for atmospheric chemistry, the most energetically favourable class of transition states vary with the number of water molecules attached. A kinetic model is utilised, taking into account the most likely outcomes of the initial SO2 O3−(H2O)n collision complexes. This model shows that the reaction takes place at collision rates regardless of the number of water molecules involved. A lifetime analysis of the collision complexes supports this conclusion. Hereafter, the thermodynamics of water and O2 condensation and evaporation from the product SO3−O2(H2O)n cluster is considered and the final products are predicted to be O2SO3− and O2SO3−(H2O)1. The low degree of hydration is rationalised through a charge analysis of the relevant complexes. Finally, the thermodynamics of a few relevant reactions of the O2SO3− and O2SO3−(H2O)1 complexes are considered.

Disulfuric acid dissociated by two water molecules: ab initio and density functional theory calculations

2015 ◽  
Vol 17 (43) ◽  
pp. 28556-28564 ◽  
Author(s):  
Seong Kyu Kim ◽  
Han Myoung Lee ◽  
Kwang S. Kim
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
New Record ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Water Molecules ◽  
Functional Theory

Superacid H2S2O7, attributed to its S–O–S torsional flexibility for many sulfone groups, is deprotonated by two water molecules, which sets a new record for the fewest number of water molecules to induce dissociation of acids.

scholarly journals Structures and reaction rates of the gaseous oxidation of SO<sub>2</sub> by an O<sub>3</sub><sup>−</sup>(H<sub>2</sub>O)<sub>0–5</sub> cluster – a density functional theory investigation

2011 ◽  
Vol 11 (11) ◽  
pp. 29647-29679 ◽  
Author(s):  
N. Bork ◽  
T. Kurtén ◽  
M. B. Enghoff ◽  
J. O. P. Pedersen ◽  
K. V. Mikkelsen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Atmospheric Chemistry ◽  
Density Functional ◽  
Transition States ◽  
Density Functional Theory Calculations ◽  
Reaction Rates ◽  
Water Molecules ◽  
Functional Theory ◽  
High Entropy ◽  
Collision Complexes

Abstract. Based on density functional theory calculations we present a study of the gaseous oxidation of SO2 to SO3 by an anionic O3−(H2On cluster, n=0–5. The configurations of the most relevant reactants, transition states, and products are discussed and compared to previous findings. Two different classes of transition states have been identified. One class is characterized by strong networks of hydrogen bonds, very similar to the reactant complexes. The other class is characterized by loose structures of hydration water and is stabilized by high entropy. At temperatures relevant for atmospheric chemistry, the most energetically favorable class of transition states vary with the number of water molecules attached. A kinetic model is utilized, taking into account the most likely outcomes of the initial SO2O3−(H2O)n collision complexes. This model shows that the reaction takes place at collision rates regardless of the number of water molecules involved. A lifetime analysis of the collision complexes supports this conclusion. Hereafter, the thermodynamics of water and O2 condensation and evaporation from the product SO3−O2(H2O)n cluster is considered and the final products are predicted to be O2SO3− and O2SO3−(H2O)1. The low degree of hydration is rationalized through a charge analysis of the relevant complexes. Finally, the thermodynamics of a few relevant reactions of the O2SO3− and O2SO3−(H2O)1 complexes are considered.

Is a Non-Transition Element Nitride Ferromagnet Ever Achievable? Indication of the N-N Pairing Instability

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1525-1531 ◽  
Author(s):  
Wojciech Grochala
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Transition Element ◽  
Density Functional Theory Calculations ◽  
Functional Theory

The enthalpy of four polymorphs of CaN has been scrutinized at 0 and 100 GPa using density functional theory calculations. It is shown that structures of diamagnetic calcium diazenide (Ca2N2) are preferred over the cubic ferromagnetic polymorph (CaN) postulated before, both at 0 and 100 GPa.

scholarly journals Tensor-structured algorithm for reduced-order scaling large-scale Kohn–Sham density functional theory calculations

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chih-Chuen Lin ◽  
Phani Motamarri ◽  
Vikram Gavini
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Large Scale ◽  
Density Functional Theory Calculations ◽  
System Size ◽  
Real Space ◽  
Functional Theory ◽  
Reduced Order ◽  
Separable Approximation ◽  
Tensor Basis

AbstractWe present a tensor-structured algorithm for efficient large-scale density functional theory (DFT) calculations by constructing a Tucker tensor basis that is adapted to the Kohn–Sham Hamiltonian and localized in real-space. The proposed approach uses an additive separable approximation to the Kohn–Sham Hamiltonian and an L1 localization technique to generate the 1-D localized functions that constitute the Tucker tensor basis. Numerical results show that the resulting Tucker tensor basis exhibits exponential convergence in the ground-state energy with increasing Tucker rank. Further, the proposed tensor-structured algorithm demonstrated sub-quadratic scaling with system-size for both systems with and without a gap, and involving many thousands of atoms. This reduced-order scaling has also resulted in the proposed approach outperforming plane-wave DFT implementation for systems beyond 2000 electrons.

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