Atomistic Simulation of Ceramic/Metal Interfaces: {222}MgO/Cu

Abstract: Atomistic simulations were performed for the {222}MgO/Cu interface by local density functional theory (LDFT) methods, within the plane-wave-pseudopotential representation, and by (classical) molecular dynamics and statics. The electronic spectra obtained with LDFT calculations showed a localized interface state within the bulk MgO gap, approximately 1 eV above the MgO valence band edge. LDFT adhesive energy calculations, as a function of interface spacing and translations parallel to the interface, were employed to devise an interatomic potential suitable for large-scale atomistic simulation. The interface structure, which was obtained with molecular dynamics (and statics) calculations based on the resultant potential, exhibited a misfit dislocation network with trigonal symmetry, and no standoff dislocations.

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Classical Interatomic Potential for Nb-Alumina Interfaces

MRS Proceedings ◽

10.1557/proc-654-aa4.3.1 ◽

2000 ◽

Vol 654 ◽

Cited By ~ 4

Author(s):

K. Albe ◽

R. Benedek ◽

D. N. Seidman ◽

R.S. Averback

Keyword(s):

Density Functional ◽

Large Scale ◽

Interatomic Potential ◽

Local Density ◽

Embedded Atom Method ◽

Metal Interface ◽

Functional Theory ◽

Embedded Atom ◽

Local Density Functional Theory ◽

Modified Embedded Atom Method

AbstractA modified-embedded-atom-method (MEAM) potential is derived for the ternary system Al-O-Nb in order to simulate the model oxide-metal interface sapphire-niobium. In the present work, MEAM parameters for Al and O given by Baskes were adopted, and the parameters for Nb are adjusted to match experimental data for pure Nb and calculated properties for Nb oxides and aluminides. The properties for niobium oxides and aluminides were obtained from local- density-functional-theory (LDFT) calculations. The resultant potential was tested in simulations for the Nb(111)/α -alumina(0001) interface. MEAM predictions of the work of separation and the interlayer relaxations for two interface terminations are in excellent agreement with LDFT calculations. The MEAM potential therefore appears suitable for large-scale computer simulation of oxide-metal interface properties.

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Beyond-dipole van der Waals contributions within the Many-Body Dispersion framework

Electronic Structure ◽

10.1088/2516-1075/ac3b5c ◽

2021 ◽

Author(s):

Dario Massa ◽

Alberto Ambrosetti ◽

Pier Luigi Silvestrelli

Keyword(s):

Density Functional ◽

Large Scale ◽

Local Density ◽

Van Der Waals ◽

Van Der Waals Interactions ◽

Many Body ◽

Full Account ◽

Local Density Functional Theory ◽

Body Level ◽

The Many

Abstract By introducing a suitable range-separation of the Coulomb coupling in analogy to [A. Ambrosetti et al. JCP 140, 18A508 (2014)], here we extend the Many-Body Dispersion (MBD) approach to include beyond-dipole van der Waals interactions at a full many-body level, in combination with semi-local density functional theory. A reciprocal-space implementation is further introduced in order to efﬁciently treat periodic systems. Consistent reliability is found frommolecular dimers to large supramolecular complexes and two-dimensional systems. The large weight of both many-body effects and multipolar terms illustrates how a correct description of vdW forces in large-scale systems requires full account of both contributions, beyond standard pairwise dipolar approaches.

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Atomic Structure of a Polar Ceramic/Metal Interface: {222}MgO/Cu

MRS Proceedings ◽

10.1557/proc-492-103 ◽

1997 ◽

Vol 492 ◽

Author(s):

R. Benedek ◽

D. A. Shashkov ◽

D. N. Seidman ◽

D. A. Muller ◽

J. Silcox ◽

...

Keyword(s):

Electron Microscopy ◽

Density Functional ◽

Interatomic Potential ◽

Local Density ◽

High Resolution Electron Microscopy ◽

Atom Probe ◽

Dislocation Network ◽

Interfacial Dislocation ◽

Probe Field ◽

Scanning Transmission

ABSTRACT{222}MgO/Cu is one of the most extensively characterized ceramic/metal interfaces, in view of the atom-probe field-ion-microscopy, Z-contrast scanning-transmission-electron-microscopy (STEM), and spatially-resolved electron-energy-loss-spectroscopy (EELS) measurements performed by the present authors, as well as the high-resolution electron microscopy (HREM) of this system by others. Atomistic simulations with local density functional theory (LDFT) and molecular dynamics (MD) have been performed to gain additional insight into the structure of this interface. This presentation describes an interface interatomic potential for {222}MgO/Cu derived from LDFT total energy calculations, and its application to structural properties, including the terminating species, the absence of dislocation standoff, and the symmetry of the interfacial dislocation network.

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On the gaussian-type orbitals approach to local density functional theory

Journal de Chimie Physique ◽

10.1051/jcp/1989860671 ◽

1989 ◽

Vol 86 ◽

pp. 671-688 ◽

Cited By ~ 62

Author(s):

B.I. Dunlap ◽

N. Rösch

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Local Density ◽

Functional Theory ◽

Gaussian Type ◽

Local Density Functional Theory ◽

Local Density Functional

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Structure and Stability of Grain Boundaries in Molybdenum with Segregated Carbon Impurities

MRS Proceedings ◽

10.1557/proc-578-405 ◽

1999 ◽

Vol 578 ◽

Cited By ~ 1

Author(s):

R. Janisch ◽

T. Ochs ◽

A. Merkle ◽

C. Elsässer

Keyword(s):

Ab Initio ◽

Grain Boundaries ◽

Density Functional ◽

Local Density ◽

Structural Parameters ◽

Carbide Phases ◽

Carbon Impurities ◽

Transmission Electron ◽

Local Density Functional Theory ◽

Symmetrical Tilt

AbstractThe segregation of interstitial impurities to symmetrical tilt grain boundaries (STGB) in bodycentered cubic transition metals is studied by means of ab-initio electronic-structure calculations based on the local density functional theory (LDFT). Segregation energies as well as changes in atomic and electronic structures at the ΣE5 (310) [001] STGB in Mo caused by segregated interstitial C atoms are investigated. The results are compared to LDFT data obtained previously for the pure Σ5 (310) [001] STGB in Mo. Energetic stabilities and structural parameters calculated ab initio for several crystalline Molybdenum Carbide phases with cubic, tetragonal or hexagonal symmetries and different compositions, MoCx, are reported and compared to recent high-resolution transmission electron microscopy (HRTEM) observations of MoCx, intergranular films and precipitates formed by C segregation to a Σ5 (310) [001] STGB in a Mo bicrystal.

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Local density-functional theory of frequency-dependent linear response

Physical Review Letters ◽

10.1103/physrevlett.55.2850 ◽

1985 ◽

Vol 55 (26) ◽

pp. 2850-2852 ◽

Cited By ~ 766

Author(s):

E. K. U. Gross ◽

Walter Kohn

Keyword(s):

Density Functional Theory ◽

Linear Response ◽

Density Functional ◽

Local Density ◽

Functional Theory ◽

Frequency Dependent ◽

Local Density Functional Theory ◽

Local Density Functional

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Bayesian active learning of interatomic force field for molecular dynamics simulation of Pt/Ag(111)

10.26434/chemrxiv-2021-sk6lf-v2 ◽

2021 ◽

Author(s):

Kai Xu ◽

Lei Yan ◽

Bingran You

Keyword(s):

Molecular Dynamics ◽

Active Learning ◽

Force Field ◽

Density Functional ◽

Process Model ◽

Large Scale ◽

Computational Cost ◽

Dynamics Simulation ◽

Potential Energy Landscape ◽

Three Body

Force field is a central requirement in molecular dynamics (MD) simulation for accurate description of the potential energy landscape and the time evolution of individual atomic motions. Most energy models are limited by a fundamental tradeoff between accuracy and speed. Although ab initio MD based on density functional theory (DFT) has high accuracy, its high computational cost prevents its use for large-scale and long-timescale simulations. Here, we use Bayesian active learning to construct a Gaussian process model of interatomic forces to describe Pt deposited on Ag(111). An accurate model is obtained within one day of wall time after selecting only 126 atomic environments based on two- and three-body interactions, providing mean absolute errors of 52 and 142 meV/Å for Ag and Pt, respectively. Our work highlights automated and minimalistic training of machine-learning force fields with high fidelity to DFT, which would enable large-scale and long-timescale simulations of alloy surfaces at first-principles accuracy.

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Structure and Electrochemical Potential Simulation for the Cathode Material Li1+xV3O8

MRS Proceedings ◽

10.1557/proc-496-115 ◽

1997 ◽

Vol 496 ◽

Cited By ~ 1

Author(s):

R. Benedek ◽

M. M. Thackeray ◽

L. H. Yang

Keyword(s):

Density Functional ◽

Structural Information ◽

Local Density ◽

Tetrahedral Site ◽

Low Energy ◽

Electrochemical Potential ◽

X Ray Diffraction ◽

X Ray ◽

Local Density Functional Theory ◽

Two Phases

ABSTRACTThe structure and electrochemical potential of monoclinic Li1+xV3O8 were calculated within the local-density-functional-theory framework by use of plane-wave-pseudopotential methods. Special attention was given to the compositions 1+x=1.2 and 1+x=4, for which x-ray diffraction structure refinements are available. The calculated low-energy configuration for 1+x=4 is consistent with the three Li sites identified in x-ray diffraction measurements and predicts the position of the unobserved Li. The location of the tetrahedrally coordinated Li in the calculated low-energy configuration for 1+x=1.5 is consistent with the structure measured by x-ray diffraction for Li1.2V3O8. Calculations were also performed for the two monoclinic phases at intermediate Li compositions, for which no structural information is available. Calculations at these compositions are based on hypothetical Li configurations suggested by the ordering of vacancy energies for Li4V3O8 and tetrahedral site energies in Li1.5V3O8. The internal energy curves for the two phases- cross near 1+x=3. Predicted electrochemical potential curves agree well with experiment.

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First-Principles-Based Interatomic Potential for SI and Its Thermal Conductivity

ASME/JSME 2011 8th Thermal Engineering Joint Conference ◽

10.1115/ajtec2011-44339 ◽

2011 ◽

Author(s):

Keivan Esfarjani ◽

Gang Chen ◽

Asegun Henry

Keyword(s):

Thermal Conductivity ◽

Molecular Dynamics ◽

Thermal Properties ◽

Force Field ◽

Molecular Dynamics Simulations ◽

First Principles ◽

Density Functional ◽

Interatomic Potential ◽

Force Constants ◽

Dynamics Simulations

Based on first-principles density-functional calculations, we have developed and tested a force-field for silicon, which can be used for molecular dynamics simulations and the calculation of its thermal properties. This force field uses the exact Taylor expansion of the total energy about the equilibrium positions up to 4th order. In this sense, it becomes systematically exact for small enough displacements, and can reproduce the thermodynamic properties of Si with high fidelity. Having the harmonic force constants, one can easily calculate the phonon spectrum of this system. The cubic force constants, on the other hand, will allow us to compute phonon lifetimes and scattering rates. Results on equilibrium Green-Kubo molecular dynamics simulations of thermal conductivity as well as an alternative calculation of the latter based on the relaxation-time approximation will be reported. The accuracy and ease of computation of the lattice thermal conductivity using these methods will be compared. This approach paves the way for the construction of accurate bulk interatomic potentials database, from which lattice dynamics and thermal properties can be calculated and used in larger scale simulation methods such as Monte Carlo.

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