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arXiv · 1608.07697

Novel dense crystalline packings of ellipsoids

Weiwei Jin·Yang Jiao·Lufeng Liu·Ye Yuan·Shuixiang Li
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Abstract

An ellipsoid, the simplest non-spherical shape, has been extensively used as models for elongated building blocks for a wide spectrum of molecular, colloidal and granular systems. Yet the densest packing of congruent hard ellipsoids, which is intimately related to the high-density phase of many condensed matter systems, is still an open problem. We discover a novel dense crystalline packing of ellipsoids containing 24 particles with a quasi-square-triangular (SQ-TR) tiling arrangement, whose packing density ϕ exceeds that of the SM2 crystal for aspect ratios α in (1.365, 1.5625), attaining a maximal ϕ about 0.75806 at α = 93/64. We show that SQ-TR phase is thermodynamically stable at high densities over the aforementioned α range and report a novel phase diagram for self-dual ellipsoids. The discovery of SQ-TR crystal suggests novel organizing principles for non-spherical particles and self-assembly of colloidal systems.

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Weiwei Jin, Yang Jiao, Lufeng Liu, Ye Yuan, Shuixiang Li. 2016-08-27. Novel dense crystalline packings of ellipsoids. https://doi.org/10.1103/physreve.95.033003

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