论文标题
X射线吸收的自适应实时时间相关密度功能理论
Self-Adaptive Real-Time Time-Dependent Density Functional Theory for X-ray Absorptions
论文作者
论文摘要
实时时间依赖性密度功能理论（RT-TDDFT）原则上可以访问暴露于狭窄脉冲的多电子系统的整个吸收光谱。但是，这需要一个准确，有效的传播器，以使时间相关的Kohn-Sham方程的数值整合。虽然低阶时间传播器已经足以容纳低洼的价吸收光谱，但即使仅由光元素组成的系统的X射线吸收光谱（XAS）不再是这种情况，而高阶传播器的使用是必不可少的。然后，选择最大的时间步骤和最短的模拟时间至关重要，以最大程度地减少计算成本。为此，我们在这里提出了一种强大的AUTOPST方法，以自动确定XAS的相对论RT-TDDFT模拟的传播器（p），步骤（s）和时间（t）。
Real-time time-dependent density functional theory (RT-TDDFT) can in principle access the whole absorption spectrum of a many-electron system exposed to a narrow pulse. However, this requires an accurate and efficient propagator for the numerical integration of the time-dependent Kohn-Sham equation. While a low-order time propagator is already sufficient for the low-lying valence absorption spectra, it is no longer the case for the X-ray absorption spectra (XAS) of systems composed even only of light elements, for which the use of a high-order propagator is indispensable. It is then crucial to choose a largest possible time step and a shortest possible simulation time, so as to minimize the computational cost. To this end, we propose here a robust AutoPST approach to determine automatically (Auto) the propagator (P), step (S), and time (T) for relativistic RT-TDDFT simulations of XAS.
