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应助: 0 (幼儿园)
金币: 18
帖子: 2
在线: 1.1小时
虫号: 1472298
注册: 2011-11-02
专业: 色谱分析

[求助] 请高手根据编辑意见帮我精修一下单晶吧，先谢谢啦

我是新手，编辑给的意见好多，我完全不知道该怎么下手啦

而且我也没有SHELXTL软件。帮帮忙吧，需要什么文件请跟我说，现在我是一头雾水了。

以下是编辑意见：（好长啊，头晕

）

1. The "_diffrn_measured_fraction_theta_full" is too low. I note you have cut off your reflection file at theta = 25.1 deg yet your unit cell determination uses reflections up to theta = 27.69 deg. I include a quote from CheckCIF relative to this point:

" Ideally (and a requirement for publication in Acta Crystallographica),
this fraction should be close to 1.0 for theta-full greater or equal
to sin(theta/lambda) = 0.6 (i.e. 25.24 degrees for MoKa and 67.7 degrees
for CuKa radiation).
The three major causes of incomplete data sets are:
1 - A missing cusp of data due to data collection by rotation around
the spindle axis only (standard on some image-plate systems).
Cure: collect an additional data set after remounting the crystal.
2 - The DENZO imageprocessing package has problems with certain strong
reflections. They are often excluded from the data set.
Cure: Add an additional scan at lower power setting in order to
include strong low order reflections.
3 - Incomplete scans, possibly based on erroneously assumed higher than
actual symmetry."
Thus your theta(max) cutoff is too low and this may be part of the problem. I am also puzzled by the small number of reflections collected. Did you collect a full sphere of data? With an APEX-II that shouldn't take an inordinate amount of time. If your present data set doesn't have enough measurable data so that you can get "_diffrn_measured_fraction_theta_full" above 0.99 at theta = 25.24 deg, it will be necessary to recollect the data using longer scan times and/or at low temperature.

2. It appears that the reflection 1 0 0 is obscured by the beamstop and should be omitted from the final refinement.

3. Please be certain that your final weighting scheme is correct (I get different values than you report in my test refinement).

4. Your Fig. 2 needs to be redrawn using circles or only the outlines of the ellipsoids, not full ellipsoids, and should include those H-atoms which are involved in the H-bonding. Also, the O2-H2...O3 interaction has too small an angle to be considered a true H-bond.

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