We present a comprehensive computational study of sp(3)-carbon allotropes based on the topologies proposed for zeolites. From ≈600,000 zeolite nets we identified six new allotropes, lying by at most 0.12 eV per atom above diamond. The analysis of cages in the allotropes has revealed close structural relations to diamond and lonsdaleite phases. Besides the energetic and mechanical stability of new allotropes, three of them show band gaps by ca. 1 eV larger than that of diamond, and therefore represent an interesting technological target as hard and transparent materials. A structural relation of new allotropes to continuous random networks is pointed out and possible engineering from diamond thin films and graphene is suggested.
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http://dx.doi.org/10.1039/c4cp04569f | DOI Listing |
Adv Mater
December 2024
King Abdullah University of Science and Technology (KAUST), Division of Physical Sciences and Engineering, Functional Materials Design, Discovery and Development Research Group (FMD3), Thuwal, 23955-6900, Kingdom of Saudi Arabia.
Here, the fundamental requirements are described for understanding and using topology tools in the design of porous materials, emphasizing the relationships between nets, metal-organic framework (MOF) structures, nodes, and building blocks. Common design approaches are discussed, highlighting prerequisites for the rational design of MOFs, such as those with simple pcu topology through the molecular building block approach, or axial-to-axial pillaring. The importance of highly connected nets and building units is emphasized for achieving structural predictability.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Jiangsu Key Laboratory of Biomedical Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, China.
The synthesis of zirconium MOFs with zeolite net is quite challenging due to the high connectivity of Zr clusters, which is far from tetrahedral connection, a requisite for zeolite net. In this work, we demonstrate a six-membered ring (6MR) strategy through mimicking of mineral zeolites with mixed ditopic and tritopic carboxylate linkers. With this strategy, the ditopic linker cross-links Zr clusters to form 4-connected zeolite-like nets, while the tritopic one is used to direct the formation of 6MR and simultaneously consumes extra coordination sites on the cluster.
View Article and Find Full Text PDFActa Crystallogr A Found Adv
January 2024
Instituto de Química, Universidade Federal do Rio de Janeiro, Avenida Athos da Silveira Ramos, 149 Bloco A, Cidade Universitária, Rio de Janeiro 21941-909, Brazil.
Löwenstein's avoidance rule in aluminosilicates is reinterpreted on the basis of the fourth Pauling rule. It is shown that avoidance of Si-O-Si bridges may account for avoidance of Al-O-Al bridges. In view of this interpretation, it is proposed that the most favourable distributions of cations entering in substitution of silicon in the framework are associated to maximal independent sets of the respective 3-periodic nets.
View Article and Find Full Text PDFActa Crystallogr A Found Adv
September 2023
Instituto de Química, Universidade Federal do Rio de Janeiro, Avenida Athos da Silveira Ramos, 149 Bloco A, Cidade Universitária, Rio de Janeiro 21941-909, Brazil.
This paper introduces a new method of determining the independence ratio of periodic nets, based on the observation that, in any maximum independent set of the whole net, be it periodic or not, the vertices of every unit cell should constitute an independent set, called here a configuration. For 1-periodic graphs, a configuration digraph represents possible sequences of configurations of the unit cell along the periodic line. It is shown that maximum independent sets of the periodic graph are based on directed cycles with the largest ratio.
View Article and Find Full Text PDFActa Crystallogr A Found Adv
July 2022
SCTMS, Samara University, Samara, 443086, Russian Federation.
Physical properties of objects depend on topological features of the corresponding triply periodic surfaces; thus topological exploration and classification of the surfaces has practical relevance. A general method is developed for generating triply periodic surfaces from triply periodic crystal structures. A triply periodic surface is derived from the natural tiling of a crystal network by an appropriate removal of some tile faces and subsequent smoothing of the resulting facet surface.
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