3d系列(TM)_4团簇的结构和磁性

Structure and magnetism of 3d series (TM)_4 clusters

基于第一性原理 ,在密度泛函理论下 ,用局域自旋密度近似 (LSDA)和广义梯度近似 (GGA)对 (TM ) 4 团簇的所有几何构型进行优化、能量、频率和磁性计算 .确定出 3d系列 (TM ) 4 团簇的基态构型 ,对其磁性、结合能和平均原子间距作了系统的研究 ,得出在 3d系列 (TM) 4 团簇中 ,Mn4 的局域磁矩最大 ,V4 的局域磁矩最小 ,并且除Cr4 在LSDA和GGA均为反铁磁性耦合及GGA下的V4 为反铁磁性耦合外 。

Based on the first-principle, we optimize all geometric structures of (TM) 4 c lusters, calculate the energy, frequency and magnetism of (TM) 4 clusters by us ing the local spin density approximation(LSDA) and generalized gradient approxim ation(GGA) density functional theory. We confirm the ground-state structures of (TM) 4 clusters, study their magnetism, binding energy and average interatomic distance systematically, and find that in the 3d series (TM) 4 clusters, the l o cal magnetic moment of Mn 4 cluster is the largest, that of the V 4 cluster is the weakest. Except that the Cr 4 cluster in LSDA and GGA shows anti-ferromag netic coupling,and the V 4 cluster in GGA shows also anti-ferromagnetic coupl ing, other clusters all show ferromagnetic coupling.