> On 23 Feb 2024, at 09:58, Winter, Graeme (DLSLtd,RAL,LSCI) > <00006a19cead4548-dmarc-requ...@jiscmail.ac.uk> wrote: > > so strictly it is possible and correct - if experimentally unlikely - to > have the situation we are discussing here occur.
I believe this is only technically possible because the MTZ format does not store esds on the unit cell parameters? In the thaumatin example processing the dataset here - https://zenodo.org/records/4916649 - assuming monoclinic symmetry results in unit cell: 58.176(2), 150.543(4), 58.2050(18), 90.0, 90.1058(9), 90.0 The situation you describe would result in for example: 58.1087(18), 150.543(4), 58.1087(15), 90.0, 90.0000(1), 90.0 and the test should really only fail for: 58.1087(18), 58.1087(18), 150.400(5), 90.0, 90.0, 90.0 i.e. where a=b have same value and esd (as they were constrained to be identical and esd on beta is 0 as it was constrained to be 90. > Telling users to “fiddle the parameters” so that the strict test is satisfied > feels like a non-ideal answer: a warning when importing such data could be > legitimate e.g. “hmm I note a = b and al=be=ga=90 _exactly_ this is unusual, > I hope you know what you are doing” rather than a flat out error I think you have misunderstood here. I was suggesting telling users to integrate/scale the data without imposing higher symmetry was the correct thing to do? I don't see how "fiddling of parameters" is required. But I agree i2 should allow an override of this test. Huw ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
