【摘要】 用密度泛函方法对过渡金属Mn5,Mn6的各种可能构型,在PW91/ZoraTZ2P水平上进行了理论研究.计算结果表明:构型是自旋变化、磁性的敏感因素,Mn5最稳定构型为弱铁磁性的三角双锥体(磁矩为3,D3h).Mn6的最稳定构型为铁磁性的畸变八面体(磁矩为16,C4v).各种异构体虽然多重度不同,但每个原子的自旋极化度均在3以上.构型稳定与否取决于原子间的交换耦合作用,而原子间的这种作用又与自旋极化度的方向、大小息息相关.更多还原

【Abstract】 Equilibrium geometries and electronic properties of transition metal clusters (Mn5, Mn6) have been investigated by means of the relativistic density functional approach. Present results show that these clusters exhibit rich structural varieties on the potential energy surfaces, while the spin polarization at each site and the corresponding magnetic moments are highly sensitive to structures. For Mn5 cluster, the most stable structure is trigonal bipyramid with spin magnetism of 3 μB, and Mn6 cluster has the most stable structure of ferromagnetic octahedron with spin magnetic moment of 16 μB. The more stable isomers of Mn5 and Mn6 correspond to different orientations of the atomic spins resulting from the interatomic exchange coupling.更多还原