A genetic algorithm for first principles global structure optimization of supported nano structures

Vilhelmsen, Lasse B.; Hammer, Bjørk

doi:10.1063/1.4886337

Cited by 195 publications

(211 citation statements)

References 53 publications

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“…A relevant challenge when dealing with clusters is their very rich polymorphism, both in the gas phase and on the surface. The problem to identify the global minimum requires, for instance, the use of genetic algorithms, as recently done for Au 10 on rutile TiO 2 [61]. This technique, however, is not only computationally extremely demanding, but accounts for the most stable isomer at a temperature of 0 K, while at finite temperatures small clusters may not be in their global minimum structure most of the time.…”

mentioning

confidence: 98%

A DFT study of Ni clusters deposition on titania and zirconia (101) surfaces

2016

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confidence: 98%

A DFT study of Ni clusters deposition on titania and zirconia (101) surfaces

2016

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“…The ReaxFF parameters for P/H systems were optimized using a modified version of the evolutionary algorithms (EA) software suite OGOLEM, 52,53 which is able to globally optimize ReaxFF parameter sets with high parallel efficiency. Based on DFT calculations for bulk black phosphorus, pristine and defected black phosphorene, blue phosphorene, phosphorus hydride molecules and phosphorus clusters, ReaxFF parameters were generated for P-P and P-H bond energies, P-P-P, H-P-P and H-P-H valence angle energies and for H-P-P-P and H-P-P-H torsion energies.…”

Section: Dft Training Of Force Fieldmentioning

confidence: 99%

“…1 were selected (starting with , , , , ). The parameters were fitted to the training set using OGOELM 52,53 .…”

Section: Dft Training Of Force Fieldmentioning

confidence: 99%

Development of a Transferable Reactive Force Field of P/H Systems: Application to the Chemical and Mechanical Properties of Phosphorene

et al. 2017

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We developed ReaxFF parameters for phosphorus and hydrogen to give a good description of the chemical and mechanical properties of pristine and defected black phosphorene. ReaxFF for P/H is transferable to a wide range of phosphorus and hydrogen containing systems including bulk black phosphorus, blue phosphorene, edge-hydrogenated phosphorene, phosphorus clusters and phosphorus hydride molecules. The potential parameters were obtained by conducting global optimization with respect to a set of reference data generated by extensive ab initio calculations. We extended ReaxFF by adding a 60° correction term which significantly improved the description of phosphorus clusters. Emphasis was placed on the mechanical response of black phosphorene with different types of defects. Compared to the nonreactive SW potential, 1 ReaxFF for P/H systems provides a significant improvement in describing the mechanical properties of the pristine and defected black phosphorene, as well as the thermal stability of phosphorene nanotubes. A counterintuitive phenomenon is observed that single vacancies weaken the black phosphorene more than double vacancies with higher formation energy. Our results also showed that the mechanical response of black phosphorene is more sensitive to defects in the zigzag direction than that in the armchair direction. Since 2 ReaxFF allows straightforward extensions to the heterogeneous systems, such as oxides, nitrides, the proposed ReaxFF parameters for P/H systems also underpins the reactive force field description of heterogeneous P systems, including P-containing 2D van der Waals heterostructures, oxides, etc.

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“…We note that the equilibrium Bi-G distance (0.33 nm) is typical of physisorbed graphene, which is dominated by vdW interactions. In turn, the Bi-G distances resulting from a 0.07 nm displacement are more characteristic of chemisorbed graphene, which is expected to hybridize more with the substrate, significantly altering the electronic structure of graphene and even leading to band gap fomation 39,40,45 . The optB88-vdW functional used in this study is able to properly describe these two bonding regimes in graphene-metal contacts 46 and remarkably, such a distortion has a relatively small energy cost (~80 meV per graphene unit cell).…”

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confidence: 99%

Band-gap engineering by Bi intercalation of graphene on Ir(111)

Warmuth¹,

Bruix²,

Michiardi³

et al. 2016

Phys. Rev. B

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*Correspondence to: a.khajetoorians@science.ru.nlWe report on the structural and electronic properties of a single bismuth layer intercalated underneath a graphene layer grown on an Ir(111) single crystal. Scanning tunneling microscopy (STM) reveals a hexagonal surface structure and a dislocation network upon Bi intercalation, which we attribute to a √3 × √3 R30 ∘ Bi structure on the underlying Ir(111) surface. Ab-initio calculations show that this Bi structure is the most energetically favorable, and also illustrate that STM measurements are most sensitive to C atoms in close proximity to intercalated Bi atoms.Additionally, Bi intercalation induces a band gap ( g = 0.42 eV) at the Dirac point of graphene 2 and an overall n-doping (~0.39 eV), as seen in angular-resolved photoemission spectroscopy.We attribute the emergence of the band gap to the dislocation network which forms favorably along certain parts of the moiré structure induced by the graphene/Ir(111) interface. by the structural confinement in graphene nanoribbons 9 10 ; by the stacking of multiple graphene layers 11,12 ; by the periodic modulation of the graphene lattice (breaking the sub-lattice symmetry), which can be achieved by using patterned substrates 13 , or through the patterned adsorption of other elements such as hydrogen 5 .Pristine graphene shows weak spin-orbit interactions 14 , but increasing the strength of these interactions could give rise to new interesting possibilities in spin-based nanoelectronics. One route toward manipulation of graphene's electronic structure is intercalation of defined The Ir(111) surface was cleaned in ultra-high vacuum (UHV) by repeated cycles of Ar sputtering, followed by annealing to 1470 K. Additionally, carbon contamination was removed, when necessary, by intermittent annealing in O 2 . A monolayer (ML) of high quality graphene was grown by exposing the clean Ir(111) surface to ethylene gas at a surface temperature of 1075 K. The growth process was followed by a short (< 30 ) rapid heating to max = 1455 K.This step increases the quality of the resulting graphene ML. Bismuth was subsequently deposited on the G/Ir(111) surface at a sample temperature of 715 K. After the deposition, the 5 sample was heated to a temperature of 1273 K for 60 s. This step leads to intercalated bismuth underneath the graphene. These surface regions where this intercalation structure is present are referred to as G/Bi/Ir throughout the text.Scanning tunneling microscopy (STM) was performed using a home-built variable temperature STM in a UHV system with a base pressure below 1 × 10 −10 mbar 20 21 . Tip and sample were cooled to = 30 K. Electrochemically etched and flashed W tips were used for all STM measurements. STM topography was recorded in constant current mode ( t ) with the bias applied to the sample ( S ). Differential conductance maps (short I/ V maps) were recorded by applying a modulation voltage ( mod ) using lock-in detection at a modulation frequency of = 5.477 kHz.ARPES data were acquired at the SGM3 beamline at ...

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A genetic algorithm for first principles global structure optimization of supported nano structures

Cited by 195 publications

References 53 publications

A DFT study of Ni clusters deposition on titania and zirconia (101) surfaces

A DFT study of Ni clusters deposition on titania and zirconia (101) surfaces

Development of a Transferable Reactive Force Field of P/H Systems: Application to the Chemical and Mechanical Properties of Phosphorene

Band-gap engineering by Bi intercalation of graphene on Ir(111)

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