摘要
基于半经验的Gupta多体势,采用遗传算法及分子动力学淬火算法,系统研究了(FeMo)m(m=38及55)双金属团簇的基态结构及其能量.结果表明:对于Fe_(n)Mo_(38-n)(n=0-38)团簇,随Fe原子数的增加,Fe原子优先占据团簇表面再占据内部,其基态构型存在类O_(h)结构、类I_(h)结构和无序结构间的竞争.对于Fe_(n)Mo_(55-n)(n=0-55)团簇,随Fe原子数的增加,Fe原子优先占据团簇中心位置,再依次占据表面顶点、棱边和次外层,双金属团簇基态构型主要体现为在Mackay二十面体基础上的结构畸变.Fe_(24)Mo_(14),Fe_(13)Mo_(42)和Fe_(43)Mo_(12)为幻数结构团簇,研究发现双金属团簇幻数成因不能通过单质团簇常用的平均配位数和平均键长模型解释,它更多的归咎于组分效应导致的结构高对称性.
The ground state structures and energies of(FeMo)m(m=38 and 55)clusters were systematically investigated by employing the genetic algorithm and molecular dynamics quenching method based on the semi empirical Gupta-type many-body potential.Results show that,for Fe_(n)Mo_(38-n)(n=0~38)clusters,with increasing of Fe atoms,Fe atoms preferentially occupy the surface of the cluster before occupying the interior,and the ground state configuration of the cluster exhibits competition between the O_(h)-like,the I_(h)-like,and the disordered structures.For Fe_(n)Mo_(55-n)(n=0~55)clusters,with increasing of Fe atoms,Fe atoms preferentially occupy the central position of the cluster,followed by surface vertices,edges,and subsurface layer,and the ground state configuration of bimetallic clusters is mainly reflected by structural distortion based on the Mackay icosahedron.Fe_(24)Mo_(14),Fe_(13)Mo_(42),and Fe_(43)Mo_(12) can be viewed as the magic-number clusters.Our finding shows that origin of magic numbers in bimetallic clusters cannot be explained by the commonly used average coordination number and average bond length models of pure clusters,and it is more attributed to the high structural symmetry caused by component effects.
作者
郑琪琪
陈轩
程彪
段海明
ZHENG Qi-Qi;CHEN Xuan;CHENG Biao;DUAN Hai-Ming(College of Physics Science and Technology,Xinjiang University,Urumqi 830017,China)
出处
《原子与分子物理学报》
CAS
北大核心
2025年第3期85-93,共9页
Journal of Atomic and Molecular Physics
基金
新疆维吾尔自治区自然科学基金(2022D01C419)。
关键词
双金属团簇
结构和能量
淬火算法
遗传算法
Bimetallic clusters
Structure and energy
Quenching algorithm
Genetic algorithm
