外电场对N@C60,P@C60,As@C60分子结构和性质的影响

Effects of Electric Field on the Structures and Electronic Properties of N@C_(60),P@C_(60) and As@C_(60)

用量子力学方法研究了N@C60,P@C60,As@C60分子的几何和电子特征.计算结果表明,形成富勒烯包合物后,碳笼只有微小的变形,3种内包原子在笼中处于不同的位置,碳笼与内包原子之间有明显的电荷转移和自旋轨道相互作用,生成能分别为6.32,70.88,-53.05 kJ/mol.内包原子的3个单占据分子轨道(SOMO)能量变化很大,并由于和碳笼作用而发生劈裂.在外电场作用下,分子的电子密度沿电场方向发生转移.分子的能量随外加电场的增强而降低.分子轨道能级、能隙及SOMO轨道的能量和能级劈裂也发生了变化.

The structural and electronic properties of N@ C60,P@ C60 and As@ C60 were investigated with quantum mechanics.Compared with isolated C60,the C60 cage deforms slightly,and the three doped atoms（N,P,As） lie in different positions in the cage.The interactions between the cage and the doped atom mainly cousist of charge transfer and spin-orbit interaction.Binding energies of these three compounds are 6.32,70.88,and-53.05 kJ/mol,respectively.The single occupied molecular orbital（SOMO） energy levels of those three doped atoms change and split because of the interaction with the cage.When electric field is applied,electron density shifts along the direction of the electric field.The energies of these molecules decrease as the electric field gets stronger.The molecular orbital energies,the gaps between the highest occupied molecular orbital and the lowest unoccupied molecular orbital,the SOMO energy levels,and the split energies va-ry considerably in the presence of electric field.