Qiu Jing, Bai Xin, Wang Linjun
Department of Chemistry , Zhejiang University , Hangzhou 310027 , China.
J Phys Chem Lett. 2018 Aug 2;9(15):4319-4325. doi: 10.1021/acs.jpclett.8b01902. Epub 2018 Jul 18.
In the traditional fewest switches surface hopping (FSSH), trivial crossings between uncoupled or weakly coupled states have highly peaked nonadiabatic couplings and thus are difficult to deal with in the preferred, adiabatic representation. Here, we classify surface crossings into four general types and propose a parameter-free crossing corrected FSSH (CC-FSSH) algorithm, which could treat multiple trivial crossings within a time interval. As examples, Holstein Hamiltonians with different parameters are adopted to mimic electron dynamics in tens to hundreds of molecules, which suffer from severe trivial crossing problems. Using existed surface hopping approaches as references, we show that CC-FSSH exhibits significantly fast time interval convergence and weak system size dependence. In all cases, a reliable description is achieved with a large time interval of 1 fs. With a simple formalism and the ability to describe complex surface crossings, CC-FSSH could potentially simulate general nonadiabatic dynamics in nanoscale materials with a high efficiency.
在传统的最少开关表面跳跃（FSSH）中，未耦合或弱耦合态之间的平凡交叉具有高度尖锐的非绝热耦合，因此在首选的绝热表示中难以处理。在这里，我们将表面交叉分为四种一般类型，并提出一种无参数交叉校正FSSH（CC-FSSH）算法，该算法可以在一个时间间隔内处理多个平凡交叉。作为示例，采用具有不同参数的荷斯坦哈密顿量来模拟数十到数百个分子中的电子动力学，这些分子存在严重的平凡交叉问题。以现有的表面跳跃方法作为参考，我们表明CC-FSSH表现出显著快速的时间间隔收敛和较弱的系统尺寸依赖性。在所有情况下，使用1 fs的大时间间隔都能实现可靠的描述。凭借简单的形式体系和描述复杂表面交叉的能力，CC-FSSH有可能高效地模拟纳米级材料中的一般非绝热动力学。
