We show how the ultrasoft pseudopotentials which have recently been proposed by Vanderbilt can be implemented efficiently in context of Car-Parrinello molecular-dynamics simulations. address differences with respect to conventional norm-conserving schemes, identify certain problems arise, and indicate these overcome. This new scheme extends possibility performing first-principles molecular dynamics systems including first-row elements transition metals.

Charge defects in water created by excess or missing protons appear the form of solvated hydronium H3O+ and hydroxyl OH− ions. Using method ab initio molecular dynamics, we have investigated structure proton transfer dynamics solvation complexes, which embed ions network hydrogen bonds liquid. In our approach, interatomic forces are calculated each time step from instantaneous electronic using density functional methods. All atoms, including proton, treated as classical particles with mass a...

An ab initio molecular dynamics simulation of liquid water has been performed using density functional theory in the Kohn–Sham formulation and a plane wave basis set to determine electronic structure forces at each time step. For an accurate description hydrogen bonding liquid, it was necessary extend exchange with term that depends on gradient electron density. A further important technical detail is supersoft pseudopotentials were used treat valence orbitals oxygen atoms expansion. The...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAb Initio Molecular Dynamics Simulation of the Solvation and Transport H3O+ OH- Ions in WaterMark Tuckerman, Kari Laasonen, Michiel Sprik, Michele ParrinelloCite this: J. Phys. Chem. 1995, 99, 16, 5749–5752Publication Date (Print):April 1, 1995Publication History Published online1 May 2002Published inissue 1 April 1995https://pubs.acs.org/doi/10.1021/j100016a003https://doi.org/10.1021/j100016a003research-articleACS PublicationsRequest reuse...

A scheme for the construction of ultrasoft separable pseudopotentials recently proposed by Vanderbilt is tested in context Car-Parrinello ab initio molecular-dynamics calculations on atoms and molecules. For case oxygen, transferability pseudopotential demonstrated comparing calculated properties molecular ${\mathrm{O}}_{2}$ ${\mathrm{O}}_{3}$ with those obtained from conventional approaches. Converged results are using plane-wave-basis cutoffs only \ensuremath{\sim}25 Ry. Forces can be...

The development of effective and inexpensive hydrogen evolution reaction (HER) electrocatalysts for future renewable energy systems is highly desired. Platinum-based materials are the most active catalyzing HER, but reducing use Pt required because high price scarcity Pt. Here, we achieve pseudo-atomic-scale dispersion Pt, i.e. individual atoms or subnanometer clusters, on sidewalls single-walled carbon nanotubes (SWNTs) with a simple readily upscalable electroplating deposition method....

Efficient hydrogen evolution reaction (HER) through effective and inexpensive electrocatalysts is a valuable approach for clean renewable energy systems. Here, single-shell carbon-encapsulated iron nanoparticles (SCEINs) decorated on single-walled carbon nanotubes (SWNTs) are introduced as novel highly active durable non-noble-metal catalyst the HER. This exhibits catalytic properties superior to previously studied nonprecious materials comparable those of platinum. The SCEIN/SWNT...

We show than an ab initio molecular-dynamics scheme based on Vanderbilt ultrasoft pseudopotentials and a plane-wave expansion for the electronic orbitals allows one to perform accurate calculations large systems containing tightly bound d-electron states. use novel real-space double-grid technique deal efficiently with localized augmentation functions in core region. apply our full simulation of liquid copper at temperature 1500 K find structural dynamical properties that are excellent...

Ab initio Car–Parrinello molecular dynamics simulations of a Li+ ion in water have been carried out using the density-functional theory with Becke–Lee–Yang–Parr (BLYP) functional and ultrasoft Vanderbildt pseudopotentials. Both structural dynamical properties studied detail compared available neutron scattering spectroscopic data. Excellent agreement is obtained existing experimental data for structure first hydration shell around ion. Spectral features bound are to those bulk water....

The pressure-induced transition of ${\mathrm{H}}_{2}$O into the ice X phase, characterized by symmetric hydrogen bonding, is studied using ab initio molecular dynamics combined with ultrasoft pseudopotentials. A good description bond obtained only after gradient corrections to local-density approximation are included. predicted at 49 GPa, in agreement experiment, when proton quantum fluctuations treated within mean-field theory. Molecular-dynamics simulations show that a mode-softening appropriate.

The structural and electronic properties of the La@C(82) fullerene have been investigated by means Car-Parrinello method, which is based on local density approximation functional theory. topological arrangement C(82) cage was assumed to be a C(3v) symmetry isomer. Three configurations were considered, one with lanthanum atom at center cluster, it along threefold axis, low-symmetry, highly coordinated site. structure fully relaxed found that last these energetically preferred. In this...

The structures of AgCu, AgNi, and AgCo nanoalloys with icosahedral geometry have been computationally studied by a combination atomistic density-functional theory (DFT) calculations, for sizes up to about 1400 atoms. These preferentially assume core–shell chemical ordering, Ag in the shell. nanoparticles can either centered or off-center cores; they an atomic vacancy their central site present different arrangements Here we compare these motifs determine factors influencing stability means...

Oxygen reduction catalyzed by cofacial metalloporphyrins at the 1,2-dichlorobenzene–water interface was studied with two lipophilic electron donors of similar driving force, 1,1′-dimethylferrocene (DMFc) and tetrathiafulvalene (TTF). The reaction produces mainly water some hydrogen peroxide, but mediator has a significant effect on selectivity, as DMFc porphyrins themselves catalyze decomposition further peroxide. Density functional theory calculations indicate that biscobaltporphyrin,...

Atomic layer deposition (ALD) is a coating technology used to produce highly uniform thin films. Aluminiumoxide, Al2O3, mainly deposited using trimethylaluminium (TMA) and water as precursors the most studied ALD-process date. However, only few theoretical studies have been reported in literature. The surface reaction mechanisms energetics previously focus on gibbsite-like model but more realistic description of can be achieved when hydroxylation taken into account dissociatively adsorbed...

The computational hydrogen evolution activity of Pt(111) remains controversial due to apparent discrepancies with experiments concerning rate-determining activation free energies and equilibrium coverages. A fundamental source error may lie within the static representations metal–water interface commonly employed in density functional theory (DFT)-based kinetic models neglecting important entropic effects on reaction dynamics. In this work, we present a dynamic reassessment Volmer–Tafel...

Acid–base properties of molecules in nonaqueous solvents are critical importance for almost all areas chemistry. Despite this very high relevance, our knowledge is still mostly limited to the pKa rather few compounds most common solvents, and a simple yet truly general computational procedure predict pKa's any compound solvent missing. In contribution, we describe such procedure. Our method requires only experimental reference water standard quantum-chemical calculations. This tested through...

The structural and dynamical properties of cubic ${\mathrm{H}}_{2}$O ${\mathrm{D}}_{2}$O ice phases are studied using ab initio molecular dynamics combined with ultrasoft pseudopotentials. Phonon frequencies extracted from the velocity autocorrelation functions; contributions different normal modes in phonon spectra separated easily identified. For low-pressure phases, agreement experimental data is reasonable isotope effects well reproduced. High-pressure also studied. equations state for...

Core-level and valence-band photoemission studies of films La@${\mathrm{xaC}}_{82}$ ${\mathrm{C}}_{82}$ demonstrate charge transfer from La to the fullerene cage formation a nonmetallic solid with uppermost band centered 0.64 eV below Fermi level. Comparison results for demonstrates that there are modifications electronic-state distribution throughout valence band. Bonding molecular radicals in pure is found be significantly stronger than empty solids which sublime at much lower...

We present results for the electronic and atomic structures of different size molecular clusters containing sulfuric acid, water, ammonia molecules. The structure calculations are performed using DMol 3 quantum chemical program packages PW91 density functional. report implications our atmospheric cluster distributions. Our indicate that is bonded to much more strongly than water. presence also strengthens binding acid molecules clusters, significantly increases formation two 0–2 water...

The realization of a hydrogen economy would be facilitated by the discovery water-splitting electrocatalyst that is efficient, stable under operating conditions, and composed earth-abundant elements. Density functional theory simulations within simple thermodynamic model more difficult half-reaction, anodic oxygen evolution reaction (OER), with single-walled carbon nanotube as catalyst, show presence 0.3-1% nitrogen reduces required OER overpotential significantly compared to pristine...

H-Adsorption on MoS₂-surfaces is studied as a function of structural parameters and an assessment the intricate structure–property relations conducted.

Abstract Electrochemical devices for efficient production of hydrogen as energy carrier rely still largely on rare platinum group metal catalysts. Chemically and structurally modified dichalcogenide MoS 2 is a promising substitute these critical raw materials at the cathode side where evolution reaction takes place. For precise understanding structure adsorption characteristics in chemically nanostructures, we perform comprehensive density functional theory calculations transition (Fe, Co,...