报告题目 (Title)：Continuous symmetry and chirality measures: Principles and applications across the natural sciences

报告人 (Speaker)：Prof. David Avnir（The Hebrew University of Jerusalem, Israel）

报告时间 (Time)：2024年6月20日（周四）17:00-19:00

报告地点 (Place)：校本部 D413

邀请人 (Inviter)：任伟 教授

主办部门：理学院物理系

报告摘要：

We have been developing the notion that structural chemistry is too rich to be described with the coarse binary language of either being or not being symmetric or chiral. We have proposed that it agrees with chemical, biochemical and physical intuition to ask questions such as: “What is the degree of symmetry content of a crystal that is described by P1 spacegroup, but clearly shows visually a near symmetry?”; “what is the symmetry content of a molecule, the structure of which cannot be described in exact symmetry terms, and how does it correlate with it physical and chemical properties?“; “given a set of chiral molecules, by how much do they differ from each other in their degree of chirality?”; and so on. Addressing the need to answer this type of structural questions, we have developed the Continuous Symmetry Measure (CSM) and the resulting Continuous Chirality Measure (CCM). In essence, the measures quantify the distance of a given structure from the desired ideal symmetry, or from achirality. It is a special distance measure, in the sense that the reference structure is not known a-priori, but searched. This approach proved useful in a number of symmetry/chirality related issues all across chemistry.

报告人简介：

David Avnir is a Professor (Em.) of Chemistry at the Institute of Chemistry, The Hebrew University of Jerusalem, where he also obtained all his academic training, and where he has held the positions of Head of the School of Chemistry, Head of the Institute of Chemistry, and Head of the Graduate School of the Experimental Sciences. His current scientific activities include solgel and aerogel materials, molecularly doped metals, chirality and symmetry in experiments and theory and astrochemistry. He has co-authored more than 400 papers, which have been cited over 40000 times, with Hirsch citation h-index of 85. Amongst his several recognitions is the Israel Chemical Society Distinction Prize (2011) and Distinguished Scientist of The Chinese Academy of Sciences (2018).