2016. 57, 5 UDC 541.67:546.74 STRUCTURES AND MAGNETIC PROPERTIES OF Nin (n = 36—40) CLUSTERS FROM FIRST-PRINCIPLES CALCULATIONS W. Song1, B. Wang1, K. Guo3, W. Zhang2 1Physics and Electronic Engineering Department, Xinxiang University, Xinxiang, P. R. China E-mail: chemsw@163.com 3The Shale Oil Plant Fushun Mining Group Co., Ltd, Fushun, P. R. China Received June, 15, 2015 2International Joint Research Laboratory of Nano-Micro Architecture Chemistry and Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin, P. R. China E-mail: zhangw_bxx@jlu.edu.cn – . 916 – 922 A genetic algorithm (GA) coupled with a tight-binding (TB) interatomic potential is used to search for the low-energy structures of medium-sized Nin (n = 36—40) clusters. <...> Structural candidates obtained from our GA search are further optimized with first-principles calculations. <...> The medium-sized nickel clusters ranging from 36 to 40 atoms are found to favor the double-icosahedron-based structures with a Ni7 core (a pentagonal bipyramidal structure) except Ni38 cluster. <...> The lowest-energy structure of Ni38 can be considered to be a magic cluster, which is a typical face-centered cubic structure with large stability and magnetic moment. <...> In particular, studies of transition metal clusters have attracted much interest. <...> However, the properties of transition metal clusters are often different from those of the corresponding bulk materials, at least in the small size range they can show a strong dependence on the cluster size. <...> Therefore in order to understand the physical and chemical properties such as catalysis, magnetic devices, and cluster assembled interfaces, it is undoubtedly important to obtain the geometrical structures of transition metal clusters [ 4—10]. <...> Among 30 kinds of pure transition metal clusters, nickel clusters are the primary target of many research groups because of their extensive catalytic and important magnetic properties. <...> However, the lowest-energy structure determination is usually a very difficult task even for clusters containing a few tens of atoms due to the rapidly increasing local minima as well as the number of structural parameters with increasing cluster size. <...> The stable geometries and magnetic moments of Nin (n <...>