有機(jī)單晶，DFT B3LYP with a 6-31G(d) basis set 計(jì)算優(yōu)化了得到了構(gòu)象和真實(shí)的單晶構(gòu)象做比較，投了篇文章。分子內(nèi)存在C-H…pi contact作用。

審稿人說分子如存在C-H…pi contact，就不能用這計(jì)算方法優(yōu)化計(jì)算，具體信息如下。 我該怎么辦呢？用什么方法計(jì)算��？看了些文獻(xiàn)可自己還是不知道怎么計(jì)算啊。非本專業(yè)麻煩各位大家?guī)臀铱纯戳?br /> 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.

我的化合物結(jié)構(gòu)式


[ Last edited by baiyuefei on 2011-6-16 at 20:32 ] 返回小木蟲查看更多