cis,cis-Ceratospongamide N,N-dimethylacetoamide hemisolvate
cis,cis-Ceratospongamide N,N-dimethylacetoamide hemisolvate

in the presence of twinning

Paper: Mitsunobu Doi, Akiko Asano & Kenji Yoza;
cis,cis-Ceratospongamide N,N-dimethylacetoamide hemisolvate in the presence of twinning
Acta Crystallographica C59, o323-o325.
Copyright © International Union of Crystallography
X-Ray Data Summary
Formula2(C41H49N7O6S), C4H9NO
Space groupP212121
Cell Crystal
a 12.6034(7) Ang. Description block
b 12.6075(7) Ang. Colour Colorless
c 53.536(3) Ang. Size (mm) 0.45x0.3x0.1
alpha 90.0 deg. Dx (g/ml) 1.267
beta 90.0 deg. F(000) 3456
gamma 90.0 deg. mu(CuKa) 0.133
volume 8506.7(8) Ang^3
Z 4
RefinementDiffrn measurement
Flack 0.09(6) Device type Bruker AXS SMART APEX
Parameters 1046 Decay 0.4 %
Restraints 0 theta max (deg.) 28.3
R_factor_gt 0.0502 No. of reflections (obs) 102830
wR_factor_gt 0.1266 No. of reflections (used) 20493
shift/su_max 0.012 e A^-3 R(int) 0.0377
DeltaRho max 0.863 e A^-3 Structure
DeltaRho min -0.274 Solution SHELXD
Measured fraction 0.985 Refinement SHELXL-97

| PDB coordinates | INS and HKL data for SHELXL97 (ZIP, 750KB) |
Twin and camera distance

This crystal was twining. The program XPREP showed the | E^2-1 | value was very lower than the resonable range as follows...

The axes of a and b were also equal in length. The refinemet was done according to the Chapter 6.7 of the SHELX-97 manual: add two instruction cards
  TWIN 0 1 0  1 0 0  0 0 -1
  BASF 0.5

We could not find any sign of twining CCD images during data collection.
cis,cis-Ceratospogaide has the long c-axis 53 A, and this axis could be trouble for data collection. In this case, spot separation was fine at 60 mm camera distance like as this. A 80 mm-camera distance was also attemped, but there was no drastic change like as this.
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Date: Jun.1998