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[求助] 请问我这个化合物该用什么方法计算，重奖！

有机单晶，DFT B3LYP with a 6-31G(d) basis set 计算优化了得到了构象和真实的单晶构象做比较，投了篇文章。分子内存在C-H…pi contact作用。

审稿人说分子如存在C-H…pi contact，就不能用这计算方法优化计算，具体信息如下。我该怎么办呢？用什么方法计算啊？看了些文献可自己还是不知道怎么计算啊。非本专业麻烦各位大家帮我看看了
1 General methodology for QM calculations. Authors should give more insights in computational details. Was located minima confirmed by frequency calculations. Have they also done wave function stability calculations for optimized structures? If not those calculations have to be done in order to fully characterize located states.
Another suggestion on how to find the conformations closest to the X-ray conformations is to start from X-ray pdb structure and see how it will be optimized within QM.

2 Chosen level for calculations. Authors are paying attention to CH…pi , assuming that they are main forces stabilizing the compound ("The conformations of molecules investigated are determined mainly by hydrogen bonds and electrostatic interactions". Indeed C-H…pi contact is mainly established by dispersion forces rather than electrostatic [1]. From this point of view chosen DFT method is not the best choice to study those compounds. DFT has its limitations to describe dispersion interaction satisfactory and requires introduction of dispersion correction. That's probably why simplistic DFT approach (B3LYP/6-31G (d)) gave poor results. Authors should approach the question of choosing right level of computations carefully.There are a couple of reviews available on this problem [2-3]. Additional calculations at higher level are reasonable and needed to complete the study.

我的化合物结构式

[ Last edited by ghcacj on 2011-6-20 at 09:46 ]

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