Expedite random structure searching using objects from Wyckoff positions

• Published in: The Journal of chemical physics 2018-02, Vol.148 (5), p.054101-054101
• Main Authors: Wang, Shu-Wei, Hsing, Cheng-Rong, Wei, Ching-Ming
• Format: Article
• Language: English
• Subjects: Carbonates; Iron carbonate; Organic chemistry; Physics; Random sampling; Searching
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.5006104

Random structure searching has been proved to be a powerful approach to search and find 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 their high-dimensional configuration space. Thus the implementations of reasonable constraints, such as adopting system symmetries to reduce the independent dimension in structural space and/or 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 either an atom or composed of a set of atoms (such as molecules or carbonates) carrying a symmetry defined by one of the Wyckoff positions of space group and through this process it allows the searching of global minimum for a complicated system to be confined in a greatly reduced structural space and becomes accessible in practice. We examined several representative materials, including Cd3As2 crystal, solid methanol, high-pressure carbonates (FeCO3), and Si(111)-7 × 7 reconstructed surface, to demonstrate the power and the advantages of using “object” concept in random structure searching.