Photodissociation of methyl iodide embedded in a host-guest complex: a full dimensional (189D) quantum dynamics study of CH3I@resorc[4]arene.
Photodissociation of methyl iodide embedded in a host-guest complex: a full dimensional (189D) quantum dynamics study of CH3I@resorc[4]arene.
复制标题
嵌入主客体复合物中的碘甲烷的光解：CH3I@resorc[4]芳烃的全维（189D）量子动力学研究。
DOI：
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发表时间：
2011
影响因子：
4.4
通讯作者：
U. Manthe
中科院分区：
文献类型：
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作者：
Till Westermann;R. Brodbeck;A. Rozhenko;W. Schoeller;U. Manthe
报道了在从头算势能面（PES）模型上研究CH（3）I@resorc[4]芳烃光解离的精确全维量子动力学计算。收敛的189维量子动力学计算是由多层多组态含时Hartree（ML-MCTDH）方法结合相关离散变量表示（CDVR）的势能矩阵元素的评估。所采用的潜力结合了一个建立的从头算PES描述的光解甲基碘在A带的间苯二酚[4]芳烃主机和双线性建模的主客体相互作用的谐波描述。在描述主体分子的振动和主体-客体相互作用中所需的所有潜在参数都来自于对主体-客体复合物的从头计算。计算了0 K和300 K下的吸收谱，研究了光激发后20-30 fs内的电子布居动力学.发现并解释了在这个时间尺度上主客体相互作用产生的微弱但显著的影响。本研究表明，精确的全量子力学动力学计算可以进行由超过50个原子组成的系统使用ML-MCTDH/CDVR方法。利用有效的统计方法构造初始波包系综，这些计算不仅限于零温度，而且还可以研究300 K下的动力学。
Accurate full dimensional quantum dynamics calculations studying the photodissociation of CH(3)I@resorc[4]arene on an ab initio based potential energy surface (PES) model are reported. The converged 189D quantum dynamics calculations are facilitated by the multilayer multi-configurational time-dependent Hartree (ML-MCTDH) approach combined with the correlation discrete variable representation (CDVR) for the evaluation of potential energy matrix elements. The potential employed combines an established ab initio PES describing the photodissociation of methyl iodide in the A band with a harmonic description of the resorc[4]arene host and a bilinear modeling of the host-guest interaction. All potential parameters required in the description of the vibrations of the host molecule and the host-guest interaction are derived from ab initio calculations on the host-guest complex. Absorption spectra at 0 K and 300 K are calculated and the electronic population dynamics during the bond breaking process occurring in the first 20-30 fs after the photoexcitation is investigated. Weak but significant effects resulting from the host-guest interaction on this time scale are found and interpreted. The present study demonstrates that accurate fully quantum mechanical dynamics calculations can be preformed for systems consisting of more than 50 atoms using the ML-MCTDH/CDVR approach. Utilizing an efficient statistical approach for the construction of the ensemble of initial wavepackets, these calculations are not restricted to zero temperature but can also study the dynamics at 300 K.