[ccp4bb]: Indexing problem

[Konstantinos Beis <kb11@st-andrews.ac.uk>]

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Dear All,
I have collected some data for a new structure and I have problems with my 
indexing. In Mosflm I get the following possible space groups:

17  59     cP   137.26   137.69   153.06    90.1  90.1  90.0 
P23,P213,P432,P4232,P4332,P4132
  16  58     hR   194.36   205.36   247.82    95.2  89.9 118.1   R3,R32
  15  58     hR   194.36   205.82   247.13    95.1  89.8 118.1   R3,R32
  14  57     tP   137.69   153.06   137.26    90.1  90.0  90.1 
P4,P41,P42,P43,P422,P4212,P4122,P41212,P4222,P42212 P4322,P43212
  13  57     oC   205.69   206.06   137.26    90.1  90.1  83.9   C222,C2221
  12  57     mC   205.69   206.06   137.26    90.1  90.1  83.9   C2
  11  56     mC   206.06   205.69   137.26    89.9  90.1  96.1   C2
  10   3     oC   194.47   194.36   153.06    90.0  90.2  89.8   C222,C2221
   9   3     tP   137.26   137.69   153.06    90.1  90.1  90.0 
P4,P41,P42,P43,P422,P4212,P4122,P41212,P4222,P42212 P4322,P43212
   8   2     mC   194.47   194.36   153.06    90.0  90.2  90.2   C2
   7   2     mC   194.47   194.36   153.06    90.0  90.2  89.8   C2
   6   1     oP   137.26   137.69   153.06    90.1  90.1  90.0 
P222,P2221,P21212,P212121
   5   1     mP   137.26   137.69   153.06    90.1  90.1  90.0   P2,P21
   4   1     mP   137.26   153.06   137.69    90.1  90.0  90.1   P2,P21
   3   1     mP   137.69   137.26   153.06    90.1  90.1  90.0   P2,P21
   2   0     aP   137.26   137.69   153.06    89.9  89.9  90.0   P1
   1   0     aP   137.26   137.69   153.06    90.1  90.1  90.0   P1


So in Mosflm from 10 to 1 I have good fitting.

When I put those data in SCALA in all the possible groups I get the following:

                                 I/sigma(overall) 
multiplicity(overall)
for p1 Rmerge of 5%             5.3                     1.7
for p21 Rmerge of 11.7%             2.3                  2.2
for c2 Rmerge of 11.7%  1.6                     2.2
for p222, p2221......   17%     1.6                     4.2
for c222, .......      17%              1.6                     4.2
for p4, ........    36%         0.8                     4.4

The I/sigma and redundancy  varies according to the space group

As you can see my a=b, which I think it causes problems with the right 
indexing..

In my Scala files it seems that I have p4 pseudosymmetry.

In the p212121 space group I have good definition for the h.


Due to that (misindexing) I have problems with my Molecular Replacement.

Is there something that I might be doing wrong or something that I have not 
noticed? Any help or suggestions are welcomed!




Kostas







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Konstantinos Beis
Centre for Biomolecular Sciences
University of St Andrews
North Haugh
St Andrews
FIFE KY16 9ST


tel: +44 1334 427265
email: kb11@st-andrews.ac.uk

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