报告题目 (Title)：Continuous symmetry and chirality measures: Principles and applications across the natural sciences（连续对称性和手性测量：原理及其在自然科学中的应用）

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.