Time-Dependent Density Matrix Renormalization Group Coupled with n-Mode Representation Potentials for the Excited State Radiationless Decay Rate:Formalism and Application to Azulene  

结合n模式表示势的含时密度矩阵重正化群求解激发态非辐射衰减速率:理论形式和在薁分子中的应用

作　　者：Jia-jun Ren Yuan-heng Wang Wei-tang Li Tong Jiang Zhi-gang Shuai 任佳骏;王远珩;李维唐;姜童;帅志刚(清华大学化学系,有机光电子与分子工程教育部重点实验室,北京100084)

机构地区：[1]MOE Key Laboratory of Organic Opto Electronics and Molecular Engineering,Department of Chemistry,Tsinghua University,Beijing 100084,China

出　　处：《Chinese Journal of Chemical Physics》2021年第5期565-582,I0002,I0003,共20页化学物理学报（英文）

基　　金：supported by the National Natural Science Foundation of China through the Project "Science Center for Luminescence from Molecular Aggregates(SCELMA)" (No.21788102);the Ministry of Science and Technology of China through the National Key R&D Plan (No.2017YFA0204501);supported by the National Natural Science Foundation of China (No.22003029)

摘　　要：We propose a method for calculating the nonradiative decay rates for polyatomic molecules including anharmonic effects of the potential energy surface(PES)in the Franck-Condon region.The method combines the n-mode repre-sentation method to construct the ab initio PES and the nearly exact time-dependent density matrix renormalization group method(TD-DMRG)to simulate quantum dynamics.In addition,in the framework of TD-DMRG,we further develop an algorithm to calculate the final-state-resolved rate coefficient which is very useful to analyze the contribution from each vibrational mode to the transition process.We use this method to study the internal conversion(IC)process of azulene after taking into account the anharmonicity of the ground state PES.The results show that even for this semi-rigid molecule,the intramode anharmonicity enhances the IC rate significantly,and after considering the two-mode coupling effect,the rate increases even further.The reason is that the anharmonicity enables the C-H vibrations to receive electronic energy while C-H vibrations do not contribute on the harmonic PES as the Huang-Rhys factor is close to 0.

关 键 词：Time-dependent density matrix renormalization group method Nonradiative decay rate Quantum dynamics Matrix product state 

分 类 号：O56[理学—原子与分子物理]