碳分子线激发态特性的TDDFT方法研究

Study on the Properties of the Excited State of Carbon Molecular Wire under External Electric Field Using TDDFT Theory

采用含时密度泛函(TDDFT)方法研究了外电场对碳分子线激发态、振子强度和偶极矩的影响,结果表明外电场的大小对碳分子线激发态激发能、振子强度等都有明显影响.碳分子线的电偶极矩随Z轴方向电场的增强而急剧增大.进一步分析表明,Z轴方向电场的存在使正负电荷分别向某端聚集,从而会对碳分子线的电子传输、伏安特性等产生一定的影响.

The effect of external electric field on the excited state, oscillator strength and dipole moment of carbon molecular wire has been studied by time dependent density functional theory （TDDFT）. It is shown that the external electric field along the Z axis markedly affects on the exited state energy and the oscillator strength of carbon molecular wire. The dipole moment of carbon molecular wire increases rapidly with increase of the electric field along Z axis. It is found that just right external electric field makes the positive charge and the negative charge congregate round some point, respectively, and affects on the electron transportation and volt-ampere characteristics of carbon molecular wire.