Development of time-dependent density functional theory for electronic and nuclear degrees of freedom : Investigation of structural deformation of molecules in intense laser fields

提出了一种适用于多组分密度泛函理论的对偶变换方法。多组分体系的模型选择为H_2^+。用基于多组分密度泛函理论的有限差分方法计算了基态的能量和几何形状。将所得结果与Born-Oppenheimer近似和精确处理的结果进行了比较。还展示了H_2~(2+)的实时动力学。对所得结果进行了讨论，并与精确解进行了比较。清楚地表明了原子核和电子之间的动态关联效应的重要性。我们还提出了一个核-电子气模型来估算核-电子关联能。在随机位相近似的框架下，导出了原子核与电子的有效相互作用的表达式。我们发现，原子核和电子之间的吸引相互作用可以被屏蔽。TH…在梯形近似下，导出了微扰能量的更多表达式。为了检验上述方法的有效性，我们发展了一种参考方法，即含时绝热态方法，其中近红外场中的电子和核动力学用含时绝热势和激光电场随时间变化引起的非绝热跃迁来描述。多原子分子的绝热态性质可以用从头算分子轨道方法计算。我们将所提出的方法应用于近红外强场中CO_2的动力学研究，发现在CO_2^&lt；2+&gt；阶段，强场诱导同时发生对称双键伸缩和大幅度弯曲运动。我们还报道了实验上观察到的乙醇在强激光作用下C-O和C-C键选择性断裂的理论研究结果。较少

We developed a dual transformation method that is applicable to multicomponent density functional theory. The model of a multicomponent system is chosen to be H_2^+. The energy and the geometry of the ground state are calculated by using the finite difference method based on multicomponent density functional theory. The results obtained were compared with those obtained from the Born-Oppenheimer approximation and those obtained by exact treatment. The real-time dynamics of H_2^+ are also demonstrated. The results obtained are discussed and compared with the exact solution. The importance of the dynamic correlation effect between nuclei and an electron is clearly shown. We also present a nucleus-electron gas model to estimate the nucleus-electron correlation energy. The expression of the effective interaction between nucleus and electron in the framework of the random-phase approximation is derived. We find that the attractive interaction between nucleus and electron can be shielded. Th … More e expression of the perturbation energy within the ladder approximation is also derived. We present a numerical procedure to calculate the correlation energy and the correlation potential between nucleus and electron, and estimate the nucleus-electron correlation potential.To examine the validity of the above methods, we developed a reference method, namely, the time-dependent adiabatic state approach, in which the electronic and nuclear dynamics in a near-infrared field is described in terms of time-dependent adiabatic potentials and nonadiabatic transitions due to temporal change in the laser electric field. The properties of the adiabatic states of polyatomic molecules can be calculated by ab initio molecular orbital methods. We applied the proposed approach to dynamics of CO_2 in near-infrared intense fields and revealed that in the CO_2^<2+> stage, simultaneous symmetric two-bond stretching followed by the occurrence of a large-amplitude bending motion is induced by an intense field. We also reported the results of theoretical investigation of experimentally observed selective cleavage of C-O and C-C bonds of ethanol in intense laser fields. Less