摘要
选取完整的单层矩形(41个碳环)石墨烯构型和完整单层正六边形(37个碳环)石墨烯构型,采用B3LYP/6-31G(d,p)方法进行几何优化,计算完整石墨烯构型的HOMO和LUMO分布、能隙及电荷分布.研究结果显示,完整的矩形石墨烯的HOMO和LUMO只分布在锯齿形边缘,能隙约0.15 eV;正六边形石墨烯的HOMO和LUMO广泛地分布在整个片层上,能隙约2.0 eV.石墨烯的几何构型包含扶手椅形边缘和锯齿形边缘,然后定义了2种描述C原子的ABEEM参数,即石墨烯边缘碳原子、内部碳原子,以及与这2种碳原子相关的键.使用ABEEM参数计算出的电荷分布与HF/STO-3G方法所计算的电荷分布相比较,得到的线性相关系数都达到了0.99以上.认为所获得的碳原子和π键ABEEM参数是合理的,可以应用于大石墨烯分子体系.
In this paper,we chose two single layer graphene models,including rectangle composed of 41 benzene rings and hexagon composed of 37 benzene rings.The models were optimized at B3LYP/6-31G（d,p） level.We obtained the HOMO,LUMO,as well as the energy gaps of normal rectangle and hexagon graphenes.It can be seen from the results that the HOMO and LUMO were localized in the edges of normal rectangle graphene and the energy gap was about 0.15eV;whereas HOMO and LUMO were widely delocalized over the normal hexagon graphene and the energy gap was about 2.0 eV.In the geometry of the graphene,there are two types of the edge.One is the zigzag edge,the other is armchair edge.The ABEEM parameters of the C atom and involved bond were defined and calibrated.The charge distributions of the graphenes were calculated by using the ABEEM model.The results are in a good agreement with those of ab initio and the coefficients of linear correlation are all up to 0.99.It can be found that the parameters of the C atoms and involved bonds are suitable,transferable,and applicable to the big graphene systems.
出处
《辽宁师范大学学报（自然科学版）》
CAS
2011年第3期306-310,共5页
Journal of Liaoning Normal University:Natural Science Edition
基金
国家自然科学基金项目(20873055
21073080)
辽宁省教育厅创新团队项目(2009T057)
