Spin contamination errors in DFT+U/plane-wave calculations for LixFeF3 systems (x = 0–1)

2021 ◽  
Author(s):  
Kohei Tada ◽  
Masahiro Mori ◽  
Shingo Tanaka
Keyword(s):  
Plane Wave ◽  
Spin Contamination

Estimation of spin contamination errors in DFT/plane-wave calculations of solid materials using approximate spin projection scheme

2021 ◽  
Vol 765 ◽  
pp. 138291
Author(s):  
Kohei Tada ◽  
Shusuke Yamanaka ◽  
Takashi Kawakami ◽  
Yasutaka Kitagawa ◽  
Mitsutaka Okumura ◽  
...  
Keyword(s):  
Plane Wave ◽  
Spin Projection ◽  
Solid Materials ◽  
Spin Contamination ◽  
Projection Scheme

Spin contamination errors on spin-polarized density functional theory/plane-wave calculations for crystals of one-dimensional materials

2019 ◽  
Vol 12 (11) ◽  
pp. 115506 ◽  
Author(s):  
Kohei Tada ◽  
Shingo Tanaka ◽  
Takashi Kawakami ◽  
Yasutaka Kitagawa ◽  
Mitsutaka Okumura ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Plane Wave ◽  
Density Functional ◽  
Functional Theory ◽  
One Dimensional ◽  
Spin Contamination ◽  
Spin Polarized

scholarly journals Extent of Spin Contamination Errors in DFT/Plane-wave Calculation of Surfaces: A Case of Au Atom Aggregation on a MgO Surface

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 505 ◽  
Author(s):  
Kohei Tada ◽  
Tomohiro Maruyama ◽  
Hiroaki Koga ◽  
Mitsutaka Okumura ◽  
Shingo Tanaka
Keyword(s):  
Plane Wave ◽  
Shell Structure ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Open Shell ◽  
Spin Projection ◽  
Functional Theory ◽  
Spin Contamination ◽  
Spin Polarized ◽  
Mgo Surface

The aggregation of Au atoms onto a Au dimer (Au2) on a MgO (001) surface was calculated by restricted (spin-un-polarized) and unrestricted (spin-polarized) density functional theory calculations with a plane-wave basis and the approximate spin projection (AP) method. The unrestricted calculations included spin contamination errors of 0.0–0.1 eV, and the errors were removed using the AP method. The potential energy curves for the aggregation reaction estimated by the restricted and unrestricted calculations were different owing to the estimation of the open-shell structure by the unrestricted calculations. These results show the importance of the open-shell structure and correction of the spin contamination error for the calculation of small-cluster-aggregations and molecule dimerization on surfaces.

Theory and Errors in Stereo Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 336-337
Author(s):  
J. M. Pankratz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Plane Wave ◽  
Focal Length ◽  
Foil Thickness ◽  
Points Of Interest ◽  
Transmission Electron ◽  
Vertical Spacing ◽  
Illuminating System

It is often desirable in transmission electron microscopy to know the vertical spacing of points of interest within a specimen. However, in order to measure a stereo effect, one must have two pictures of the same area taken from different angles, and one must have also a formula for converting measured differences between corresponding points (parallax) into a height differential.Assume (a) that the impinging beam of electrons can be considered as a plane wave and (b) that the magnification is the same at the top and bottom of the specimen. The first assumption is good when the illuminating system is overfocused. The second assumption (the so-called “perspective error”) is good when the focal length is large (3 x 107Å) in relation to foil thickness (∼103 Å).

A hybrid Gaussian and plane wave density functional scheme

1997 ◽  
Vol 92 (3) ◽  
pp. 477-487 ◽  
Author(s):  
GERALD LIPPERT ◽  
JuRG HUTTER ◽  
MICHELE PARRINELLO
Keyword(s):  
Plane Wave ◽  
Density Functional ◽  
Functional Scheme

Evolution of the electronic structure of metallic multilayers from two to threedimensionality. A Full Potential Linearized Augmented Plane Wave calculation.

2002 ◽  
Vol 727 ◽  
Author(s):  
A. M. Mazzone
Keyword(s):  
Plane Wave ◽  
Density Of States ◽  
Noble Metals ◽  
Full Potential ◽  
Metallic Multilayers ◽  
Augmented Plane Wave ◽  
Narrow Bandwidth ◽  
Epitaxial Multilayers ◽  
Linearized Augmented Plane Wave ◽  
Wave Calculation

AbstractFull Potential Linearized Augmented Plane Wave calculations have been performed for epitaxial multilayers formed by the noble metals Ag and Cu with a thickness n up to 10 layers. The multilayers have a fcc lattice and are pure or compositionally modulated with a structure of the type Agn Cun or (AgCu)n. For n in the range 2,3 the density of states, evaluated at paramagnetic level, exhibits a sharp reduction of the bandwidth which is consistent with the reduced coordination of these structures. For n ≤ 5 the density of states in the central layers converges to the bulk value while the outer layers retain the narrow bandwidth found at n=2. Due to the absence of charge intermixing and hybridization, these features are shared by multilayers of all composition.

Interstitial vs. Substitutional Metal Insertion in V2O5 as Post-Lithium Ion Battery Cathode: A Comparative GGA/GGA+U Study with Localized Bases

2020 ◽  
Author(s):  
Daniel Koch ◽  
Sergei Manzhos
Keyword(s):  
Electronic Structure ◽  
Plane Wave ◽  
Transition Metal Oxides ◽  
Reasonable Agreement ◽  
Correction Term ◽  
Lithium Ion ◽  
Generalized Gradient ◽  
Main Group Metals ◽  
Generalized Gradient Approximation ◽  
Metal Insertion

<p></p><p>The generalized gradient approximation (GGA) often fails to correctly describe the electronic structure and thermochemistry of transition metal oxides and is commonly improved using an inexpensive correction term with a scaling parameter <i>U</i>. We tune <i>U</i> to reproduce experimental vanadium oxide redox energetics with a localized basis and a GGA functional. We find the value for <i>U</i> to be significantly lower than what is generally reported with plane-wave bases, with the uncorrected GGA results being in reasonable agreement with experiments. We use this computational setup to calculate interstitial and substitutional <a>insertion energies of main group metals in vanadium pentoxide</a> and find <a>interstitial doping to be thermodynamically favored</a>.</p><p></p>

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