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leooo

木虫 (小有名气)

[交流] 求助一个有机分子精修的问题

最近投一篇Acta E的文章,编辑对精修方法不满意,要求详细描述,通过咨询解单晶的老师,给编辑进行了如下回复(老师写的):

When the hydrogen atoms was placed at the calculated positions, the maximum shift for H3 has arrived at the level of 3.587, however, other H atoms bonded to C atoms are within the suitable arrange. So the H3 bonded to C16 was found according to Q peaks and further refined.

编辑还是不满意,回复如下:

The _publ_section_exptl_refinement does not give clear information about how each type of H atoms were refined and the description is still not completely consistent with the atomic coordinates table. Unfortunately I was unable to understand the statement about the treatment of the H3 atom, and justification of its refinement is not clear.

同解单晶的老师交流后,大致了解到精修的过程为:
    经过理论加氢后,由于H3的椭球漂移(有可能表述不准确),导致(Δ/σ)max=3.587,所以又利用Q峰(具体是什么不清楚,老师解释是衍射实验得到的实际数据)将H3进行了固定,从而将(Δ/σ)max控制在< 0.001,老师认为这种精修方法很常见,不需要特别描述。

所以想请问,各位在精修中有没有遇到类似的问题,编辑的问题该怎么去回答。
下面是送稿中的Refinement部分:

H atoms treated by a mixture of independent and constrained refinement, with C—H 0.95 (Caromatic), 0.98 (Cmethyl), 1.00 (CH), N—H 0.85 (N1), 0.88 (N3) Å, and Uiso(H) = 1.2Ueq(C) [1.5Ueq(C) for methyl H atoms]. When the hydrogen atoms was placed at the calculated positions, the maximum shift for H3 has arrived at thelevel of 3.587, however, other hydrogen atoms bonded to Carbon atoms are within the suitable arrange. So the H3 bonded to C16 was found according to Q peaks and further refined.

我认为对精修方法的描述确实没达到要求,因为以前没有接触过,请教高手具体该怎样来描述,先谢过了。
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leooo

木虫 (小有名气)

引用回帖:
Originally posted by xi2004 at 2009-5-11 20:38:
非常奇怪. 如果 H3 was placed at the calculated position, 那它就不应该被refined, 所以就不会有 the maximum shift for H3 has arrived at the level of 3.587 的问题.
你想想, 没有refined, 其位置和ueq怎么 ...

我有点不明白你说的,不过解单晶的老师告诉我的是在进行理论加氢后,又进行了精修,按你说的就不需要精修了,全部都理论加氢就行了。可能我水平太差理解不了你的意思,能描述的简单点么。
Chemical is powerful~
4楼2009-05-11 23:29:56
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wmt1447

荣誉版主 (职业作家)

你英语还不错,翻译基本符合要求!!
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2楼2009-05-11 20:08:49
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xi2004

至尊木虫 (职业作家)

★ ★
leooo(金币+2,VIP+0): 5-11 23:30
非常奇怪. 如果 H3 was placed at the calculated position, 那它就不应该被refined, 所以就不会有 the maximum shift for H3 has arrived at the level of 3.587 的问题.
你想想, 没有refined, 其位置和ueq怎么会变?

而如果H3后来如作者说的 the H3 bonded to C16 was found according to Q peaks and further refined. 那它在刚开始refine时才可能飘, 导致shift过大.
xi2004-emuch@163.com
3楼2009-05-11 20:38:55
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mengxianggao

木虫 (正式写手)

新手

★ ★ ★
paopaomeng(金币+1,VIP+0):谢谢交流 5-13 21:00
leooo(金币+2,VIP+0): 6-1 16:00
用DFIX限制精修试试看如何。没有必要写复杂了。
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5楼2009-05-12 07:24:29
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