There is a significant problem that affects the autoindexing in the latest release of iMosflm (Version 1.0.6, March 2012).
The indexing solutions themselves are not affected, but the suggested solution (highlighted in blue) will, in some cases, be a solution with a higher symmetry than the true solution. This will be indicated by the fact that the penalty for the suggested solution will be significantly higher than for lower symmetry solutions.
An example is shown below, where iMosflm is suggesting the orthorhombic face centred solution (number 6, oF) which has a penalty of 20, while the correct solution is in fact the C face centred monoclinic solution (number 2). This happens because of a bug in the code and because the rms error on spot positions (sigma(x,y)) for the oF solution is not much higher than that for the triclinic solution.
Therefore the solution suggested by the latest iMosflm release needs to be examined critically. In the example below, the jump in penalty in going from solution 2 (penalty 1) to solution 3 (penalty 15) strongly suggests that the correct solution is number 2.
Indexing in background jobs with ipmosflm is not affected by this error.
Apologies to all those that have downloaded this new version. A bug release, that corrects this problem, will be available soon.
Thanks to Frank von Delft for bringing this to our attention, mea culpa. Andrew Leslie
<<inline: indexing_solution_failure.tiff>>
