Plasser Felix, Crespo-Otero Rachel, Pederzoli Marek, Pittner Jiri, Lischka Hans, Barbatti Mario
Interdisciplinary Center for Scientific Computing, Ruprecht-Karls-University , Im Neuenheimer Feld 368, 69120 Heidelberg, Germany.
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
J Chem Theory Comput. 2014 Apr 8;10(4):1395-405. doi: 10.1021/ct4011079. Epub 2014 Mar 13.
Surface hopping dynamics methods using the coupled cluster to approximated second order (CC2), the algebraic diagrammatic construction scheme to second order (ADC(2)), and the time-dependent density functional theory (TDDFT) were developed and implemented into the program system Newton-X. These procedures are especially well-suited to simulate nonadiabatic processes involving various excited states of the same multiplicity and the dynamics in the first excited state toward an energetic minimum or up to the region where a crossing with the ground state is found. 9H-adenine in the gas phase was selected as the test case. The results showed that dynamics with ADC(2) is very stable, whereas CC2 dynamics fails within 100 fs, because of numerical instabilities present in the case of quasi-degenerate excited states. ADC(2) dynamics correctly predicts the ultrafast character of the deactivation process. It predicts that C2-puckered conical intersections should be the preferential pathway for internal conversion for low-energy excitation. C6-puckered conical intersection also contributes appreciably to internal conversion, becoming as important as C2-puckered for high-energy excitations. In any case, H-elimination plays only a minor role. TDDFT based on a long-range corrected functional fails to predict the ultrafast deactivation. In the comparison with several other methods previously used for dynamics simulations of adenine, ADC(2) has the best performance, providing the most consistent results so far.
利用耦合簇近似二阶方法（CC2）、二阶代数图示构建方案（ADC(2)）和含时密度泛函理论（TDDFT）的表面跳跃动力学方法已被开发并应用于程序系统Newton-X中。这些程序特别适合模拟涉及相同多重性的各种激发态的非绝热过程，以及第一激发态向能量最小值或直至发现与基态交叉区域的动力学过程。选择气相中的9H-腺嘌呤作为测试案例。结果表明，ADC(2)动力学非常稳定，而CC2动力学在100飞秒内失败，这是由于准简并激发态情况下存在数值不稳定性。ADC(2)动力学正确地预测了失活过程的超快特性。它预测C2-褶皱锥形交叉点应该是低能激发下内转换的优先途径。C6-褶皱锥形交叉点对内转换也有显著贡献，对于高能激发来说，其重要性与C2-褶皱相当。在任何情况下，氢消除仅起次要作用。基于长程校正泛函的TDDFT无法预测超快失活。与先前用于腺嘌呤动力学模拟的其他几种方法相比，ADC(2)具有最佳性能，提供了迄今为止最一致的结果。
