Towards a grammar of inorganic structure
Towards a grammar of inorganic structure
复制标题
走向无机结构语法
DOI：
--
复制
发表时间：
1984
期刊：
影响因子：
--
通讯作者：
J. Klinowski
中科院分区：
文献类型：
--
作者：
A. Mackay;J. Klinowski
摘要无机晶体的描述已经从早期的集中在连接对称多面体的图片，我们概述了几个进一步的系统可视化无机结构，讨论它们的相对有用性，并提请注意曲率的概念在理解无机和生物结构的“语法”的价值。“字母”是原子，“单词”是最小的键合原子簇。“语法”是单词组合成更大单位的方式，“句法”是组织的下一个层次。这里我们不谈“意义”代表什么，但语言的隐喻是非常富有成效和启发性的。自从发现DNA的作用以来，这个比喻已经在分子生物学中牢固地建立起来。我们现在认为它在无机领域也是有用的。这种“语法”的一个重要元素是内在曲率，它可以被认为是由相邻组件的失配引起的结构中的应变的度量。我们特别集中于结构化的这一要素，而忽略了其他许多需要进一步发展的要素。例如，在平板（例如硅酸盐片结构）中的应变，除了使它们成为圆柱形之外，还可以使它们弯曲成椭圆形，产生封闭的域（例如球晶或二十面体病毒颗粒）或双曲线进入第三维，产生周期性的最小表面。周期性最小表面作为主要的二级结构出现在脂质、溶致胶体（“皂”）、骨架硅酸盐（沸石分子筛）和许多其他系统中。我们描述了一些最小的表面，并显示如何他们的配置文件和面积可以计算数值。更进一步，3D结构到4D结构的曲率很难想象，但这个概念仍然很重要。一个曲率的结构到一个不相容曲率的结构的映射可以被看作是可能的反应或变换的基础。
Abstract The description of inorganic crystal has moved on from the early concentration on a picture of linked symmetrical polyhedra, and we outline several further systems for visualising inorganic structures, discuss their relative usefulness and draw attention to the value of the concepts of curvature in understanding the “grammar” underlying inorganic and biological structure. The “letters” are the atoms and the “words” are the smallest clusters of bonded atoms. “Grammar” is the way in which the words are combined into larger units and “syntax” is the next level of organisation. We will not here touch on what “meaning” represents, but the metaphor of language is immensely productive and suggestive. Since the discovery of the role of DNA, this metaphor has become firmly established in molecular biology. We suggest now that it is useful also in the inorganic field. One important element of this “grammar” is intrinsic curvature , which can be considered as a measure of strain in structures caused by a misfit of neighbouring components. We concentrate particularly on this element of structuration at the expense of many others which would require lengthly development. For example, strain in flat sheets (for instance silicate sheet structures), besides making them cylindrical, may make them curve either elliptically, producing closed domains (such as spherulites or icosahedral virus particles) or hyperbolically into the third dimension, yielding periodic minimal surfaces. Periodic minimal surfaces occur as a dominant secondary structure in lipids, lyotropic colloids (“soaps”), framework silicates (zeolite molecular sieves) and many other systems. We describe a number of minimal surfaces and show how their profiles and areas can be calculated numerically. Going a step further, the curvature of 3-D structures into 4-D is difficult to imagine, but this concept is nevertheless important. The mapping of a structure of one curvature onto a structure of an incompatible curvature may be seen as the basis for possible reactions or transformations.