报告题目：Random Structure Searching With Object

报 告 人：魏金明 研究员（Academia Sinica）

主    办：物理工程学院、激光研究所

时    间：2017年5月15日 下午4：00

地    点：物理楼313报告厅

报告摘要：

Random structure searching has been proved to be a powerful approach to search the global minimum and the metastable structures. A true random sampling is in principle needed yet it would be highly time consuming and/or practically impossible to find the global minimum for the complicated systems in its 3-N high-dimensional structural space. Thus the implementations of reasonable constraints, such as adopting system symmetries to reduce the independent dimension in structural space and imposing chemical information to reach and relax into low-energy regions, are the most essential issues in the approach. In this paper, we propose the concept of object which is composed by an atom or a set of atoms (such as molecules or carbonates) carrying symmetry defined by one of the Wyckoff letters and thus the searching of global minimum for a large system in a greatly-reduced structural space is accessible in practice. We have examined several representative materials including Cd₃As₂ crystal, solid methanol, high-pressure carbonates (FeCO₃) and Si(111)-7x7 surface structures to demonstrate the power and the advantages of using object concept.