【摘要】 采用生长法和替代法相结合的方式构建AlnTi2团簇的可能候选构型,并在密度泛函理论基础上对其优化得到一系列各尺寸团簇的平衡几何结构.通过分析这些结构可以发现通过在Aln+1Ti团簇结构上的替代一个Ti原子的方式所构成的模型占据了AlnTi2团簇稳定结构的主导地位.另外,通过计算平均结合能,二阶差分能和分裂能分析掺杂2个Ti原子之后团簇的稳定性,结果指出掺杂2个Ti原子可以增加团簇的稳定性,并且与相邻团簇相比,Al4,6,9Ti2团簇具有较高的稳定性.更多还原

【Abstract】 All of the possible condition models were constructed by using the growing method(GM) combined with substitution method,and they were optimized on the denstity-funtional theory with the generalized gradient approximation,then the most stable structures and two typical stable isomers of AlnTi2(n =2 ~11) clusters were obtained for each size. The optimized geometries revealed that the Ti substituted Aln + 1Ti clusters for different sized AlnTi2clusters were dominant growth patterns. Moreover,the binding energies of Aln + 2,Aln + 1Ti and AlnTi2clusters illustrated that the two Ti-doped AlnTi clusters had more stabilities than the pure Aln + 2clusters and even more stability than the Aln + 1Ti clusters. And the second order energies and fragment energies illustrated that the Al4,6,9Ti2 clusters keep higher stability compared with their neighboring clusters.更多还原