【摘要】 采用密度泛函理论（DFT）中的B3P86方法,在6-311++G（d,p）基组水平上优化手性左旋体丝氨酸（S-Ser）分子、正负一价离子、负二价离子的基态稳定几何构型,并用含时密度泛函理论（TD-DFT）方法,计算手性S-Ser分子及S-Ser^2-轨道跃迁等单重低激发态特性.结果表明:手性S-Ser分子和S-Ser^2-结构参数随分子体系俘获电子数目的增加而发生变化,其中键长R变化最明显;分子轨道（MO）结合自然跃迁轨道（NTO）特征分析法可较好地描述手性S-Ser体系各激发态的电子激发特性,对Rydberg激发特征指认效果较好.更多还原

【Abstract】 Using the B3 P86 method of density functional theory, the author optimized the ground state stable geometric configuration of S-Serine（S-Ser） molecules and charged ions at the level of 6-311++G（d,p） basis set. At the same time, the method of time dependent density functional theory（TD-DFT） was used to study the low excited state properties of the S-Ser molecule and ion. The results show that the structural parameters of the S-Ser molecule and S-Ser^2- change with the increase of the number of electrons captured in the molecular system, such as the bond length R is the most obvious change. The molecular orbital（MO） combined with natural transition orbital（NTO） characteristic analysis method can better describe the electronic excitation characteristics of each excited state of S-Ser system, and the identification effect for Rydberg excitation characteristics is better.更多还原