Fast Real-Time Time-Dependent Density Functional Theory Calculations with the Parallel Transport Gauge
Fast Real-Time Time-Dependent Density Functional Theory Calculations with the Parallel Transport Gauge
复制标题
使用并行传输规进行快速实时瞬态密度泛函理论计算
DOI：
10.1021/acs.jctc.8b00580
复制
发表时间：
2018
影响因子：
5.5
通讯作者：
Lin, Lin
中科院分区：
文献类型：
--
作者：
Jia, Weile;An, Dong;Wang, Lin-Wang;Lin, Lin
由于电子波函数的快速振荡，实时时变密度泛函理论（RT-TDDFT）在数值模拟中需要非常小的时间步长（阿秒或更小），这极大地限制了它在超快动力学研究中的适用范围。在本文中，我们证明了通过使用平行输运形式优化规范选择可以大大减少这种振荡。因此，使用并行传输规范和隐式积分器的组合可以显著加速RT-TDDFT计算，并且由此产生的方案可用于加速使用Schrödinger表示的任何电子结构软件。以吸收光谱、超短激光脉冲和Ehrenfest动力学计算为例，我们表明，使用平面波基集，新方法可以利用10-100阿秒的时间步长。由于时间步长的显著增加，我们还证明，与用于32到1024个原子的硅系统的标准显式四阶龙格-库塔时间积分器相比，新方法在挂钟时间方面快了10倍以上。
Real-time time-dependent density functional theory (RT-TDDFT) is known to be hindered by the very small time step (attosecond or smaller) needed in the numerical simulation, because of the fast oscillation of electron wave functions, which significantly limits its range of applicability for the study of ultrafast dynamics. In this paper, we demonstrate that such oscillation can be considerably reduced by optimizing the gauge choice using the parallel transport formalism. RT-TDDFT calculations can thus be significantly accelerated using a combination of the parallel transport gauge and implicit integrators, and the resulting scheme can be used to accelerate any electronic structure software that uses a Schrödinger representation. Using absorption spectrum, ultrashort laser pulse, and Ehrenfest dynamics calculations for example, we show that the new method can utilize a time step that is on the order of 10–100 attoseconds using a planewave basis set. Thanks to the significant increase of the size of the time step, we also demonstrate that the new method is more than 10 times faster, in terms of the wall clock time, when compared to the standard explicit fourth-order Runge–Kutta time integrator for silicon systems ranging from 32 to 1024 atoms.