中文摘要：

用从头算理论和弹性散射格林函数的方法,计算电场作用下的1,4-苯二甲氰分子体系的电子结构及其电导和电流.结果表明：电场使体系在分子和电极间存在电荷转移和重新分布,分子与电极接触面附近出现电子积聚区和电子耗散区,从而产生附加电偶极子,对分子的电导和电流产生抑制.此外,对分子轨道能级和分子与电极的耦合系数的影响也比较明显,导致分子的伏-安特性在考虑电场作用前后有一定的差异.

英文摘要：

With ab initio theory and elastic scattering Green＇s function method, electronic structure, conductance and current of 1,4- phenylene diisocyanide molecule are investigated. It shows that charge of system is transferred and redistributed by electric field. Electron gathering area and dissipation area are formed near interface between molecule and electrodes. Additional electric dipoles are formed, which restrain conductance and current of molecule. Moreover, molecular orbit energy and coupling coefficients between molecule and electrodes are influenced obviously by electric field, which make differences in molecular voltage current characteristic.