团簇Al_(6)M_(8)(M=Li,Be,B,C,N,O)结构与性质的第一性原理研究

Structure and Properties of Al_(6)M_(8)(M=Li,Be,B,C,N,O)Clusters Based on First-principles

以八面体Al6团簇为基底,考虑第三周期元素对其的掺杂形成初始Al_(6)M_(8)(M=Li,Be,B,C,N,O)团簇,利用基于密度泛函理论的第一性原理对其结构优化,并对稳定性和电偶极性进行计算,结果显示:Al_(6)Li_(8)、Al_(6)B_(8)和Al_(6)O_(8)团簇的构型比较紧凑,Al_(6)Be_(8)、Al_(6)C_(8)和Al_(6)N_(8)团簇为笼状结构,除Al_(6)Be_(8)具有自旋三重态外,其余尺寸均为自旋单态.另外,掺杂团簇在随M元素原子序数增加的过程中,能隙值除N掺杂情况外呈逐渐增加趋势,电偶极矩表现出局部振荡行为,而极化率表现出逐渐降低的演化规律.

In this paper,the octahedral Al6 cluster is taken as the base,considering the doping of the third period element to form the initial Al_(6)M_(8)(M=Li,Be,B,C,N,O)cluster,and the first principles of density functional theory are used to optimize its structure,the stability,and electric dipolarity are calculated.The results show that,the configurations of Al_(6)Li_(8),Al_(6)B_(8)and Al_(6)O_(8)cluster is relatively com⁃pact,at the same time,the structures of Al_(6)Be_(8),Al_(6)C_(8)and Al_(6)N_(8)cluster exhibits cage-like motifs,and these clusters have spin singlet,except for Al_(6)Be_(8)which has a spin triplet.In addition,the energy gap value increases gradually with the increasing of the atomic number of M element,except for the case of N doping,the electric dipole moment shows a local oscillation behavior,and the polarization of the cluster shows a gradual decrease of evolution rule.