Ab Initio Multiple Spawning Photochemical Dynamics of DMABN Using GPUs
Ab Initio Multiple Spawning Photochemical Dynamics of DMABN Using GPUs
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DOI：
10.1021/acs.jpca.6b09962
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发表时间：
2017-01-12
影响因子：
2.9
通讯作者：
Martinez, Todd J.
中科院分区：
文献类型：
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作者：
Curchod, Basile F. E.;Sisto, Aaron;Martinez, Todd J.
采用从头多次生成 (AIMS) 方法，结合 GPU 加速线性响应时间相关密度泛函理论 (LR-TDDFT)，研究了光激发后 4-(N,N-二甲基氨基)苯甲腈 (DMABN) 的超快衰变动力学。我们针对这种情况验证了 LR-TDDFT 方法，然后对第一个近似 200 fs 的 DMABN 激发态动力学进行了详细分析。从 S-2（最初的点状亮态）到 S-1 的几乎完全非绝热群体转移发生在不到 50 fs 的时间内，二甲氨基 (DMA) 基团没有明显的扭转。仅在核波包达到 S-1 并获得局部激发电子特征后，才能观察到 DMA 基团的显着扭转。我们的结果表明，DMA 基团的扭转并不是 DMABN 中非绝热跃迁的先决条件，尽管这种运动确实与最低激发态 (S-1) 相关。
The ultrafast decay dynamics of 4-(N,N-dirnethylamino)benzonitrile (DMABN) following photoexcitation was studied with the ab initio multiple spawning (AIMS) method, combined with GPU-accelerated linear-response time-dependent density functional theory (LR-TDDFT). We validate the LR-TDDFT method for this case and then present a detailed analysis of the first approximate to 200 fs of DMABN excited-state dynamics. Almost complete nonadiabatic popiilation transfer from S-2 (the initially ptipulated bright state) to S-1 takes place in less than 50 fs, without significant torsion of the dimethylamino (DMA) group. Significant torsion of the DMA group is only observed after the nuclear wavepacket reaches S-1 and acquires locally excited electronic character. Our results show that torsion of the DMA group is not prerequisite for nonadiabatic transitions in DMABN, although such motion is indeed relevant on the, lowest excited state (S-1).