摘要
由于导电高分子是宽能带体系,紧束缚近似下的Su-Schrieffer-Heeger(缩写为SSH)模型存在一系列问题,需要加以改进才能满意地研究导电高分子的一维晶格的不稳定性。本工作将稳定晶格的Wannier函数方法加以推广,用来计算不稳定晶格的电子能带。数值结果表明,本方法的收敛性很快,取到三近邻时,能带的准确度可优于1％。同时能很精确地确定不稳定性所引起的二聚化。
It is needed to improve the tight-binding SSH model which is used to describe the conducting polymers, since the conducting polymers are the systems with wide energy band. In order to study one-dimensional lattice instability of conducting polymers more precisely, it is necessary to go beyond the tight-binding approximation. In this paper the Wannier function method used in stable lattice is extended to calculate the electron energy band of insta-ble lattice. The numerical results show that our method has good convergence, the accuracy can be better than 1% when the third neighbor is included. Meanwhile the dimerization caused by the lattice instability can also be determined precisely.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第5期796-807,共12页
Acta Physica Sinica
基金
国家自然科学基金
863计划资助的课题
