[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*To*: Erica Ollmann Saphire <erica@scripps.edu>*Subject*: cad in R32/ccp4 asymmetric units*From*: Erica Ollmann Saphire <erica@scripps.edu>*Date*: Mon, 27 Sep 1999 17:39:02 -0700 (PDT)*cc*: "'ccp4bb@dl.ac.uk'" <ccp4bb@dl.ac.uk>*In-Reply-To*: <9859F0BB0CB8D211B5430008C7B178006A5C08@srint3.sri.org>*Sender*: owner-ccp4bb@dl.ac.uk

*** For details on how to be removed from this list visit the *** *** CCP4 home page http://www.dl.ac.uk/CCP/CCP4/main.html *** Dear experts: I am running cad on a data set in the space group R32 and am wondering why cad does what it does. For example, input.mtz has these two reflections first: 4 -2 6 4 -1 -7 with a certain F and sigF. output.mtz (output from cad) has these two reflections first, with the same F and sigF as the first dataset, so they ought to be equivalent: 2 2 6 3 1 -7 with the same F and sigF So, the question is, how are these reflections equivalent? The matrix that transforms a reflection from the first set (hkl) into the reflection in the second set (HKL) is: H=h+k K=-k L=l or: 1 1 0 0 -1 0 0 0 1 This isn't one of the symmetry operators for R32. But, if I'm thinking about this correctly, this matrix transforms in reciprocal space, so the transpose matrix should apply in real space. The transpose of that matrix should be: 1 0 0 1 -1 0 0 0 1 But, that's not one of the symmetry operators for R32 either. The documentation for cad says the following: Uses: 2. Unless otherwise instructed, the program places output data in the CCP4 asymmetric unit (which sometimes differs from that in the International Tables), and sorts it to a standard order. So, I'm assuming that cad is putting this into an asymmetric unit which differs from that in the Tables. Can anyone tell me what asymmetric unit CCP4 uses for R32? and why? Thanks for your wisdom! Erica Ollmann Saphire TSRI

**References**:**SFALL Bug***From:*"Borhani, David" <borhani@sri.org>

- Prev by Date:
**problem with scaleit** - Next by Date:
**molecular replacement non-standard symmetry** - Prev by thread:
**SFALL Bug** - Next by thread:
**problem with scaleit** - Index(es):