中文摘要：

以1，8-辛二硫醇分子为研究对象，在第一性原理基础上，利用弹性散射格林函数方法，研究了1，8-辛二硫醇分子在金原子团簇上不同取向对该分子结电输运特性的影响。计算结果表明，分子与金原子团簇表面之间方位角的不同会导致分子结构、电子结构的改变，从而影响分子体系的电输运特性。当1，8-辛二硫醇分子S-S轴线与金（111）面的法线成25°夹角时，所得到的电流-电压曲线与实验值符合较好。

英文摘要：

Basing on elastic scattering Green function theory and ab initio method, we have investigated electronic transport properties of metal-molecule-metal junctions by taking the 1, 8-octanedithiol molecule as an example. The results show that the different orientation of the molecule results in the changes of the molecular geometric and electronic structures, and further influences the current-voltage characteristics of the junction. When the angle between the S-S axis of 1, 8-octanedithiol molecule and the normal direction of the gold （111） surface is 25°, the calculated current-voltage curve consists with the experimental results preferably.