# Closing Gaps in Geometrically Frustrated Symmetric Clusters: Local Equivalence between Discrete Curvature and Twist Transformations

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Fang, Fang, Clawson, Richard and Irwin, Klee. 2018. "Closing Gaps in Geometrically Frustrated Symmetric Clusters: Local Equivalence between Discrete Curvature and Twist Transformations." Mathematics. 6, pp. 1-19. https://doi.org/10.3390/math6060089
Article Title Closing Gaps in Geometrically Frustrated Symmetric Clusters: Local Equivalence between Discrete Curvature and Twist Transformations 213646 Article Fang, Fang (Author), Clawson, Richard (Author) and Irwin, Klee (Author) Mathematics 6, pp. 1-19 89 19 2018 MDPI AG Switzerland 2227-7390 https://doi.org/10.3390/math6060089 https://www.mdpi.com/2227-7390/6/6/89 In geometrically frustrated clusters of polyhedra, gaps between faces can be closed without distorting the polyhedra by the long established method of discrete curvature, which consists of curving the space into a fourth dimension, resulting in a dihedral angle at the joint between polyhedra in 4D. An alternative method—the twist method—has been recently suggested for a particular case, whereby the gaps are closed by twisting the cluster in 3D, resulting in an angular offset of the faces at the joint between adjacent polyhedral. In this paper, we show the general applicability of the twist method, for local clusters, and present the surprising result that both the required angle of the twist transformation and the consequent angle at the joint are the same, respectively, as the angle of bending to 4D in the discrete curvature and its resulting dihedral angle. The twist is therefore not only isomorphic, but isogonic (in terms of the rotation angles) to discrete curvature. Our results apply to local clusters, but in the discussion we offer some justification for the conjecture that the isomorphism between twist and discrete curvature can be extended globally. Furthermore, we present examples for tetrahedral clusters with three-, four-, and fivefold symmetry. quasicrystals; geometric frustration; space packing; tetrahedral packing; discrete curvature; twist transformation 499999. Other mathematical sciences not elsewhere classified Quantum Gravity Research, United States University of Southern Queensland University of Southern Queensland

https://research.usq.edu.au/item/q799x/closing-gaps-in-geometrically-frustrated-symmetric-clusters-local-equivalence-between-discrete-curvature-and-twist-transformations

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