Evolutionary search for (M©B16)Q (M = Sc–Ni; Q = 0/−1) clusters: bowl/boat vs. tubular shape

2019 ◽  
Vol 21 (40) ◽  
pp. 22618-22628 ◽  
Author(s):  
Zabiollah Mahdavifar ◽  
Fazel Shojaei
Keyword(s):  
Dft Calculations ◽  
Evolutionary Algorithm ◽  
Evolutionary Search ◽  
Spin Polarized ◽  
Tubular Shape

Via an evolutionary algorithm (USPEX) combined with spin-polarized DFT calculations, it was found that M doping significantly modified the shape of the well-known 2D B16.

Density functional theory calculations of atomic, electronic and thermodynamic properties of cubic LaCoO3and La1−xSrxCoO3surfaces

RSC Advances ◽  
2015 ◽  
Vol 5 (1) ◽  
pp. 760-769 ◽  
Author(s):  
Shuguang Zhang ◽  
Ning Han ◽  
Xiaoyao Tan
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Properties ◽  
Dft Calculations ◽  
Phase Diagrams ◽  
Thermodynamic Stability ◽  
Electronic Structures ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Spin Polarized

Spin-polarized DFT calculations were used to investigate the atomic, electronic structures of LaCoO3and La1−xSrxCoO3surfaces. The thermodynamic stability of these surfaces was analyzed with phase diagrams. Influence of Sr-doping was also examined.

scholarly journals Direct Evolutionary Search for Nash Equilibria Detection

2016 ◽  
Vol 11 (4) ◽  
pp. 472
Author(s):  
Rodica Ioana Lung
Keyword(s):  
Normal Form ◽  
Evolutionary Algorithm ◽  
Numerical Experiments ◽  
Nash Equilibria ◽  
Search Algorithm ◽  
Direct Method ◽  
Evolutionary Search ◽  
Normal Form Game ◽  
Tournament Selection ◽  
A Direct Method

<p>A Direct method of computing mixed form Nash equilibria of a normal form game by using a simple evolutionary algorithm is proposed. The Direct Evolutionary Search algorithm (DES) uses a generative relation for Nash equilibria with binary tournament selection and uniform mutation. Numerical experiments are used to illustrate the efficiency of the method.</p>

DFT STUDY OF METHYL (CH3) AND HYDROXYL (OH) ADSORPTION ON A GOLD (001) SURFACE

2019 ◽  
Vol 26 (05) ◽  
pp. 1850198 ◽  
Author(s):  
G. B. BOUKA-PIVOTEAU ◽  
M. N’DOLLO ◽  
B. R. MALONDA-BOUNGOU ◽  
B. MALOUMBI ◽  
P. S. MOUSSOUNDA ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Surface Energy ◽  
Dft Calculations ◽  
Adsorption Energy ◽  
Energy Surface ◽  
Geometrical Parameters ◽  
Oh Radical ◽  
Spin Polarized ◽  
Surface Dipole ◽  
Adsorption Energies

We used the DACAPO code with the GGA-PW91 approximation to study the adsorption of methyl (CH3) and hydroxyl (OH) for four- and five-layer gold (Au) (001) slabs. We have determined for each species the best binding site, adsorption energy, the change in the work function, surface energy, surface dipole moment, geometrical parameters and projected density of states (PDOS). We performed spin-unpolarized and spin-polarized DFT calculations for free and adsorbed CH3 and OH species. The most important point is that the spin polarization diminishes the adsorption energies but does not change the geometrical parameters. For the CH3 species, only the top site was found to be stable for different coverages. We found that during the optimization phase, the hollow and bridge sites were found to be unstable. In both cases the CH3 species moves toward the top site. We observe that the adsorption energy decreases when increasing the coverage. However, the OH species was stable in all investigated sites (top, bridge and hollow). We notice that the adsorption energy is dependent on the number of slab layers and the bridge is the best site in adsorption energy. The analysis of the calculated O PDOS of OH radical shows a mixing between the O orbitals and the Au bands.

scholarly journals Tunable spin-polarized band gap in Si2/NiI2 vdW heterostructure

RSC Advances ◽  
2020 ◽  
Vol 10 (15) ◽  
pp. 8927-8935 ◽  
Author(s):  
Douglas Duarte de Vargas ◽  
Rogério José Baierle
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Van Der Waals ◽  
Functional Theory ◽  
Spin Polarized ◽  
Structural And Electronic Properties ◽  
Vdw Heterostructure

Using density functional theory (DFT) calculations we investigate the structural and electronic properties of a heterogeneous van der Waals (vdW) structure consisting of silicene and NiI2 single layers.

scholarly journals Tuning the Electrochemical Properties of Organic Battery Cathode Materials: Insights from Evolutionary Algorithm DFT Calculations

ChemSusChem ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2402-2409 ◽  
Author(s):  
Rodrigo P. Carvalho ◽  
Cleber F. N. Marchiori ◽  
Daniel Brandell ◽  
C. Moyses Araujo
Keyword(s):  
Dft Calculations ◽  
Electrochemical Properties ◽  
Evolutionary Algorithm ◽  
Cathode Materials

scholarly journals Evolutionary Algorithm Based Residual Block Search for Compression Artifact Removal

2020 ◽  
Author(s):  
Rishil Shah
Keyword(s):  
Image Compression ◽  
Evolutionary Algorithm ◽  
Evolutionary Search ◽  
Residual Network ◽  
Deep Convolutional Neural Networks ◽  
Artifact Removal ◽  
Compressed Images ◽  
Block Based ◽  
Residual Block ◽  
Computational Resources

<div>Lossy image compression is ubiquitously used for</div><div>storage and transmission at lower rates. Among the existing</div><div>lossy image compression methods, the JPEG standard is the most widely used technique in the multimedia world. Over the years, numerous methods have been proposed to suppress the compression artifacts introduced in JPEG-compressed images. However, all current learning-based methods include deep convolutional neural networks (CNNs) that are manually-designed by researchers. The network design process requires extensive computational resources and expertise. Focusing on this issue, we investigate evolutionary search for finding the optimal residual block based architecture for artifact removal. We first define a residual network structure and its corresponding genotype representation used in the search. Then, we provide details</div><div>of the evolutionary algorithm and the multi-objective function</div><div>used to find the optimal residual block architecture. Finally, we present experimental results to indicate the effectiveness of our approach and compare performance with existing artifact removal networks. The proposed approach is scalable and portable to numerous low-level vision tasks.</div>

Polymorphs of two dimensional phosphorus and arsenic: insight from an evolutionary search

2017 ◽  
Vol 19 (18) ◽  
pp. 11282-11288 ◽  
Author(s):  
Suhas Nahas ◽  
Akash Bajaj ◽  
Somnath Bhowmick
Keyword(s):  
Density Functional Theory ◽  
Evolutionary Algorithm ◽  
Crystal Structures ◽  
Density Functional ◽  
Evolutionary Search ◽  
Two Dimensional ◽  
Functional Theory ◽  
Extensive Search

Using an evolutionary algorithm, in conjunction with density functional theory (DFT) based electronic, ionic and cell relaxation, we perform an extensive search for the crystal structures of possible two dimensional (2D) allotropes of phosphorus and arsenic.

scholarly journals Properties of Reaction Intermediates from Unzipping Nanotubes via the Diketone Formation: A Computational Study

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Takashi Yumura ◽  
Toshiyuki Kanemitsu
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Computational Study ◽  
Tube Axis ◽  
Reaction Intermediates ◽  
Frontier Orbitals ◽  
Functional Theory ◽  
Large Hole ◽  
Armchair Nanotubes ◽  
Spin Polarized

We investigated properties of an armchair nanotube attached by specific numbers of diketone groups along the tube axis using density functional theory (DFT) calculations. The results from DFT calculations show that multiple diketone attachments into an armchair nanotube cleave the CC bonds along the tube axis, forming a large hole. Then, the six-membered rings surrounding the hole are planarized, and zigzag edges appear. Due to these geometrical changes, the functionalized armchair nanotubes exhibit properties similar to those in corresponding graphene ribbons with zigzag edges. For example, diketone-attached nanotubes have a spin-polarized ground state with frontier orbitals whose amplitudes are localized at diketone O atoms. As a consequence of the existence of the localized orbitals, unpaired electrons appear only on the diketone O atoms in an armchair nanotube.

scholarly journals An Extension of Geiringer's Theorem for a Wide Class of Evolutionary Search Algorithms

2006 ◽  
Vol 14 (1) ◽  
pp. 87-118 ◽  
Author(s):  
Boris Mitavskiy ◽  
Jonathan Rowe
Keyword(s):  
Evolutionary Algorithm ◽  
Wide Class ◽  
Transition Matrix ◽  
General Theorem ◽  
Search Space ◽  
Evolutionary Search ◽  
Mild Conditions ◽  
Markov Transition Matrix ◽  
Markov Transition ◽  
The Family

The frequency with which various elements of the search space of a given evolutionary algorithm are sampled is affected by the family of recombination (reproduction) operators. The original Geiringer theorem tells us the limiting frequency of occurrence of a given individual under repeated application of crossover alone for the classical genetic algorithm. Recently, Geiringer's theorem has been generalized to include the case of linear GP with homologous crossover (which can also be thought of as a variable length GA). In the current paper we prove a general theorem which tells us that under rather mild conditions on a given evolutionary algorithm, call it A, the stationary distribution of a certain Markov chain of populations in the absence of selection is unique and uniform. This theorem not only implies the already existing versions of Geiringer's theorem, but also provides a recipe of how to obtain similar facts for a rather wide class of evolutionary algorithms. The techniques which are used to prove this theorem involve a classical fact about random walks on a group and may allow us to compute and/or estimate the eigenvalues of the corresponding Markov transition matrix which is directly related to the rate of convergence towards the unique limiting distribution.

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