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各位大神以及sob老师好，小弟是做有机合成的，对计算刚刚接触，看到一篇文献的supportinginformation中提到明态（S bright state）暗态（S dark state）以及detachment/attachment density analysis，对这三个概念不太理解其含义，也试图搜索过，并没有找到答案，还请大神们赐教。不胜感激，小弟CSC德国读博，如有意愿的也可联系，提供无偿帮助
关于下图和文献内容小弟有以下几个问题：
1. 明态（S bright state）和暗态（S dark state）分别的含义是什么，明态是否就是指S1（第一单重激发态）？
2. 作者在利用“detachment/attachment density analysis”对“hole (A) and electron (B) wavefunctions”进行近似，这个“detachment/attachment density analysis”和“hole (A) and electron (B) wavefunctions”又指的是什么，和HOMO\LUMO轨道能级图又有啥关系？
以下是问下原文和图：
For consistent and accurate description of the many different states involved in the singlet fission process, we have employed several methods, all rooted in density functional theory (DFT), to help us identify key intermediate states. More specifically, we use regular DFT calculations for the S0 and T1 states, linear response time-dependent (TD) DFT53 for the Sbright state, and constrained DFT approach54 for the T1T1 state. All calculations are done with the package QChem at the level of B3LYP/6-31G*. Complete results for the model system BTDO2 are provided. All molecular geometries used in calculations are fully optimized, and all energy values are presented as calculated without adjustment. Because most implementations of TDDFT do not provide access to doubly excited states,56 we are unable to calculate the S dark state.
Scheme S1. Initial and Final Electronic States. After optical excitation (hν) the singlet
charge transfer exciton (S bright|CT) is formed. The hole (A) and electron (B)
wavefunctions are approximated with detachment/attachment density analysis. (C) The
iSF process results in conversion of the Sbright state (1.52 eV) to a pair of localized triplets
(2 T1) with a total energy of 1.43 eV. The detrimental internal conversion (IC) pathway,
which competes with iSF on a sub-picosecond timescale in some systems, is also
displayed. We note that the states displayed here are the initial and final electronic states
in the iSF process. The transition from singlet exciton to triplet pair does not occur
directly; a more detailed discussion of the iSF mechanism is included in the SI section.
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发表于 Post on 2018-1-12 05:37:35
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发表于 Post on 2018-1-12 12:52:46
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