“…Furthermore, we note that the atoms of the substrate can also react to the presence of the deposited atoms or molecules and thus move out of their original positions into new equilibrium positions of the substrate + deposit system-in the extreme case (if the atoms are allowed to move freely during a global optimization), these atoms will leave the substrate and become part of the layer on top of the substrate (and, conversely, atoms of the deposit will enter the substrate) [53]. Typical examples of global or very low-energy minimum structures for a large variety of one-dimensional siliconcarbon chains (after final minimization of the DFTB energy in three dimensions) [37]. Si and C atoms are depicted as large red and small blue spheres, respectively.…”
Section: Classes Of Low-dimensional Systemsmentioning
confidence: 99%
“…Be, Mg and O atoms are shown as blue, red and purple spheres, respectively. In order to indicate possible distortions in the hexagons towards two highly distorted squares, all cation–anion distances up to 3 Å are drawn in the figures as red (Mg-O) and blue (Be-O) lines; for undistorted hexagons, the distance between opposite cations and anions always exceeds 3 Å.Figure 5Various global and low-energy minima for Be n Mg 12-n O 12 on cylinders of various radii [37]: ( a ) n = 1, 2, 3, 4, 5, 7; ( b ) n = 8, 9, 10, 11. Note that square, hexagonal and mixed patterns (including octagons) are found.…”
Section: Examplesmentioning
confidence: 99%
“…(a) Pure one-dimensional systems As a first example of a pure one-dimensional system, we consider finite chains of silicon and carbon atoms, Si n C m of various lengths n + m ≤ 15 [37]. As energy function, we employ DFTB, as implemented in the DemonNano algorithm [55], and the global exploration was performed using simulated annealing with periodic stochastic quenches, where jump moves were allowed, as implemented in the G42 + global landscape exploration package [56].…”
Section: Examplesmentioning
confidence: 99%
“…Methods for performing such unbiased structure predictions have been developed and applied for 35 years by now, where the focus of the applications has been on atom clusters in vacuum [31][32][33], single molecules and biomolecules [34][35][36] and crystalline compounds [12,26,29,34]. Yet in recent years, low-dimensional systems have become of great interest [37]. In this work, we discuss some of the special aspects that distinguish the structure prediction of low-dimensional systems from those of three-dimensional bulk solids, clusters and single molecules, and present a number of prototypical example systems.…”
Section: Introductionmentioning
confidence: 99%
“…Figure1. Typical examples of global or very low-energy minimum structures for a large variety of one-dimensional siliconcarbon chains (after final minimization of the DFTB energy in three dimensions)[37]. Si and C atoms are depicted as large red and small blue spheres, respectively.…”
Structure prediction of stable and metastable polymorphs of chemical systems in low dimensions has become an important field, since materials that are patterned on the nano-scale are of increasing importance in modern technological applications. While many techniques for the prediction of crystalline structures in three dimensions or of small clusters of atoms have been developed over the past three decades, dealing with low-dimensional systems—ideal one-dimensional and two-dimensional systems, quasi-one-dimensional and quasi-two-dimensional systems, as well as low-dimensional composite systems—poses its own challenges that need to be addressed when developing a systematic methodology for the determination of low-dimensional polymorphs that are suitable for practical applications. Quite generally, the search algorithms that had been developed for three-dimensional systems need to be adjusted when being applied to low-dimensional systems with their own specific constraints; in particular, the embedding of the (quasi-)one-dimensional/two-dimensional system in three dimensions and the influence of stabilizing substrates need to be taken into account, both on a technical and a conceptual level.
This article is part of a discussion meeting issue ‘Supercomputing simulations of advanced materials’.
“…Furthermore, we note that the atoms of the substrate can also react to the presence of the deposited atoms or molecules and thus move out of their original positions into new equilibrium positions of the substrate + deposit system-in the extreme case (if the atoms are allowed to move freely during a global optimization), these atoms will leave the substrate and become part of the layer on top of the substrate (and, conversely, atoms of the deposit will enter the substrate) [53]. Typical examples of global or very low-energy minimum structures for a large variety of one-dimensional siliconcarbon chains (after final minimization of the DFTB energy in three dimensions) [37]. Si and C atoms are depicted as large red and small blue spheres, respectively.…”
Section: Classes Of Low-dimensional Systemsmentioning
confidence: 99%
“…Be, Mg and O atoms are shown as blue, red and purple spheres, respectively. In order to indicate possible distortions in the hexagons towards two highly distorted squares, all cation–anion distances up to 3 Å are drawn in the figures as red (Mg-O) and blue (Be-O) lines; for undistorted hexagons, the distance between opposite cations and anions always exceeds 3 Å.Figure 5Various global and low-energy minima for Be n Mg 12-n O 12 on cylinders of various radii [37]: ( a ) n = 1, 2, 3, 4, 5, 7; ( b ) n = 8, 9, 10, 11. Note that square, hexagonal and mixed patterns (including octagons) are found.…”
Section: Examplesmentioning
confidence: 99%
“…(a) Pure one-dimensional systems As a first example of a pure one-dimensional system, we consider finite chains of silicon and carbon atoms, Si n C m of various lengths n + m ≤ 15 [37]. As energy function, we employ DFTB, as implemented in the DemonNano algorithm [55], and the global exploration was performed using simulated annealing with periodic stochastic quenches, where jump moves were allowed, as implemented in the G42 + global landscape exploration package [56].…”
Section: Examplesmentioning
confidence: 99%
“…Methods for performing such unbiased structure predictions have been developed and applied for 35 years by now, where the focus of the applications has been on atom clusters in vacuum [31][32][33], single molecules and biomolecules [34][35][36] and crystalline compounds [12,26,29,34]. Yet in recent years, low-dimensional systems have become of great interest [37]. In this work, we discuss some of the special aspects that distinguish the structure prediction of low-dimensional systems from those of three-dimensional bulk solids, clusters and single molecules, and present a number of prototypical example systems.…”
Section: Introductionmentioning
confidence: 99%
“…Figure1. Typical examples of global or very low-energy minimum structures for a large variety of one-dimensional siliconcarbon chains (after final minimization of the DFTB energy in three dimensions)[37]. Si and C atoms are depicted as large red and small blue spheres, respectively.…”
Structure prediction of stable and metastable polymorphs of chemical systems in low dimensions has become an important field, since materials that are patterned on the nano-scale are of increasing importance in modern technological applications. While many techniques for the prediction of crystalline structures in three dimensions or of small clusters of atoms have been developed over the past three decades, dealing with low-dimensional systems—ideal one-dimensional and two-dimensional systems, quasi-one-dimensional and quasi-two-dimensional systems, as well as low-dimensional composite systems—poses its own challenges that need to be addressed when developing a systematic methodology for the determination of low-dimensional polymorphs that are suitable for practical applications. Quite generally, the search algorithms that had been developed for three-dimensional systems need to be adjusted when being applied to low-dimensional systems with their own specific constraints; in particular, the embedding of the (quasi-)one-dimensional/two-dimensional system in three dimensions and the influence of stabilizing substrates need to be taken into account, both on a technical and a conceptual level.
This article is part of a discussion meeting issue ‘Supercomputing simulations of advanced materials’.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
