| Abstract: | The electronic structure of C60 adsorbed on Ag(111) surface have beencalculated by using Discrete Variational-Local Density Functional method(DV-LDF).The STMimages have been obtained by calculating the charge density distributions of thesystem,which based on the Tersoff-Hamann theory.The results show that there is 2.32etransfer from Ag cluster surface to C60.The STM images are sensitive to thepolarity of external electric field.In the positive bias voltage case,there is threefive-membered rings around the topmost in the calculated charge distribution of LUMO andit reflects the symmetry of adsorbed molecular.This means that the tunneling current comemainly from the single bond.However,in the negative bias case,the STM image show that thetopmost six-membered ring is highlighted with a center hole just like a doughnut.We find agood agreement between the STM images observed and the calculated charge distributions ofHOMO and LUMO. |
