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The First Table of Atomic Site Coordinates of the Ih QC (3)

已有 421 次阅读 2026-10-17 20:28 |个人分类:AEC 原子环境计算|系统分类:论文交流

The First Table of Atomic Site Coordinates of the Ih QC (3)

https://doi.org/10.5281/zenodo.23426598

The First Table of Atomic Site Coordinates of the Ih Quasicrystal | Zenodo

Table 4.1. Crystallographic characteristics of the QC (Ih) Cell

In an isolated QC (Ih) cell consisting of 30 shells, the lattice is entirely equivalent to that of a conventional crystal, characterized by unit cell parameters:  a=b=c=1.3800, corresponding to d=1 in the first table and α=β=γ=92.874, occupying positions 1a and 3e, and belonging to space group No. 166.  Cluster structure analysis further indicates that an individual quasicrystal (QC) cell is, in fact, a conventional crystal.

"Site: u,v,w=",5,4,3

"dist of the site from the center of QC,|Puvw|=",9.12410125390449

"   x=",4.19119990737601

"   y=",2.42705097891877

"   z=",7.73256041513044

"Site: u,v,w=",5,4,2

"dist of the site from the center of QC,|Puvw|=",8.45254566530233

"   x=",3.92833434938673

"   y=",1.61803398594585

"   z=",7.30723500948024

"Site: u,v,w=",5,3,3

"dist of the site from the center of QC,|Puvw|=",8.39318343911167

"   x=",3.34054909902398

"   y=",2.42705097891877

"   z=",7.30723501095442

"Site: u,v,w=",4,4,3

"dist of the site from the center of QC,|Puvw|=",8.3333983612796

"   x=",4.19119990737601

"   y=",2.42705097891877

"   z=",6.78150389883529

"Site: u,v,w=",6,4,3

"dist of the site from the center of QC,|Puvw|=",9.9429339799478

"   x=",4.19119990737601

"   y=",2.42705097891877

"   z=",8.68361693142559

"Site: u,v,w=",5,5,3

"dist of the site from the center of QC,|Puvw|=",9.89251920062829

"   x=",5.04185071572805

"   y=",2.42705097891877

"   z=",8.15788581930646

"Site: u,v,w=",5,4,4

"dist of the site from the center of QC,|Puvw|=",9.8418461760666

"   x=",4.4540654653653

"   y=",3.2360679718917

"   z=",8.15788582078063

 

It follows that Pauling’s main argument at the time was correct: quasicrystals with icosahedral symmetry (Ih) are indeed composed of 20 coherently intergrown conventional crystals—though these crystals do not belong to the cubic crystal system, but rather to the trigonal crystal system.

A very practical question is: how can the coordinates of these 5,083 atomic sites be verified? My answer is simple.

The first method can be done using just a calculator.  Within the same shell, the nearest-neighbor distance between all atomic sites is 1; the nearest-neighbor distance between atomic sites located in different shells is 0.951056516.

The second method employs the Ih point group for verification; however, it must be emphasized that when deriving the matrices for the Ih point group, one must ensure that the Cartesian coordinate system used is entirely consistent with the Cartesian coordinate system of the n-shell lattice model.

    Third, using a lattice model that lacks Ih point-group symmetry to verify a lattice model with Ih symmetry is not a good choice.

     14年前,我证明鲍林关于准晶体的论述,主要观点是正确的,14年后的今天,我再次证明,鲍林的“多重孪晶”的观点是正确的,唯一的缺憾是鲍林选错孪生对象(对称性),是三方对称性,属于D3d点群,而非立方对称性的Oh点群。

     我建议了三种方法来验证我的

The First Table of Atomic Site Coordinates of the Ih Quasicrystal | Zenodo

1)就用一个小学生的计算器来验证:准晶体一层(n=2),一层(n=3),一层(n=4)地平移向外扩展,一直到充满整个空间,始终要保持层内最近邻距离为1, 层间最近邻距离为0.951056516295154。始终保持这个条件,直到充满整个空间,这就是满足Ih点群对称性的空间点阵。

2)用Ih点群验证:我那些坐标数据,就是Ih点群生成的。解铃还须系铃人,这系铃人就是Ih点群。但是,有很多细节,关于Ih点群的细节,需要真正的把握。

3) Third, using a lattice model that lacks Ih point-group symmetry to verify a lattice model with Ih symmetry is not a good choice.

  这第三就是,用一个不具有Ih点群对称性的点阵模型来检验一个具有Ih点群对称性的点阵,不是一种明知的选择。

 

 关于点群对称性的故事,有2700年的历史了。

  • 卞和献玉(具象的完美): 卞和所献的“和氏璧”代表了中国传统文化中对玉石(天然晶体)的最高追求——温润、纯净、无瑕。在古人眼中,这是自然界鬼斧神工的具象完美。

  • 伽罗华发表群论(抽象的对称):      19世纪,天才数学家伽罗华为了解决五次方程的根式解问题,创立了群论(Group      Theory)。群论是现代数学中研究“对称性”的核心工具。它将人类对美的感知(如玉石的对称、晶体的几何美感)上升到了极其严密的抽象数学高度。

  • 谢赫特曼发现准晶体(对称的颠覆与重塑):      1982年,谢赫特曼在电子显微镜下看到了颠覆传统晶体学常识的“五次对称”衍射图形。在古典晶体学中,这种对称性是被数学定理判定为“不可能存在”的。然而,正是利用伽罗华群论延伸出的高维空间投影几何,科学家们最终完美解释了准晶体(Quasicrystal)的数学结构。谢赫特曼借此重构了人类对物质结构的认知,并荣获2011年诺贝尔化学奖。

·        楚国的卞和: 坚信石头里包裹着绝世美玉,两次献宝却被玉工诬陷为“诳也”(骗子),惨遭砍去双足。直到文王即位,剖开璞玉,才见和氏璧。他用鲜血和双足捍卫了晶体的内在价值。

·        法国的伽罗华: 他的群论手稿远远超越了那个时代,曾被数学大师柯西和傅里叶遗失或拒绝,甚至被评价为“无法理解”。他在决斗前夜绝望地写下“我没有时间了”,20岁便英年早逝。直到十几年后,他的理论才被后人理解,成为现代物理和数学的基石。

·        美国的谢赫特曼: 当他发现准晶体时,当时的科技界巨头、两届诺贝尔奖得主鲍林(Linus Pauling)曾公开嘲笑他:“没有准晶体,只有准科学家。”谢赫特曼甚至因此被他的研究小组开除。但他顶住了长达数年的孤立与质疑,最终证实了自己是正确的。

 

           以上是Al总结的,不够到位,适当的时候,我会亲自来用点群的思想,把2700年的点群故事串起来。

       实际上,我在《魔方和数学建模》第五讲已经讲述了一遍,我讲的比Al要动听多了。



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