An ab initio study of niobium(n=2-11)clusters:structure,stability and magnetism

• 来源期刊: 中国物理B（英文版）
• 关键词: Nbn cluster density functional theory structure stability and magnetism
• 年，卷（期）: 2009,（4）
• 页码范围: 1491-1497
• 页数: 7页
• 语种: 英文

摘要

The ground-state configurations of the Nbn(n2-11)clusters are studied through the first-principles calculations.It is found that niobium clusters(n=2-11)tend to form compact structures with low symmetry.The clusters with 4,8 and 10 atoms axe found to be magic and have relatively large highest occupied-lowest unoccupied molecular orbital(HOMO-LUMO)gaps.The Nbn clusters possess low magnetic moments,which exhibit an odd-even oscillational character.The analyses of calculated electronic density and population of the lowest-energy niobium clusters for n=2,3,5,7,9,11 show that the total magnetic moments of Nbn originate mainly from a few Nb atoms with longer spacings between them in most cases,while thcy are located on two Nb atoms for n=2,3,5.The total magnetic moments come mainly from the 4d local moments but with the exception of the Nb5 cluster.