SHELX C/D/E: Difference between revisions

101 bytes added ,  7 June 2023
m
→‎Minimum distance between atoms (MIND): remove "(as in the above thaumatin example" because that does not exist
m (→‎Minimum distance between atoms (MIND): remove "(as in the above thaumatin example" because that does not exist)
(3 intermediate revisions by the same user not shown)
Line 97: Line 97:
A common 'user error' is to set MIND -3.5 even though the distances between heavy atoms are less than 3.5 Å.  For example, in a Fe<sub>4</sub>S<sub>4</sub> cluster the Fe...Fe distance is about 2.7 Å, so MIND -2 would be appropriate. A disulfide bond has a length of 2.03 Å so then MIND -1.5 could be used to resolve the sulfur atoms, however if DSUL is used for this purpose MIND -3.5 is required.
A common 'user error' is to set MIND -3.5 even though the distances between heavy atoms are less than 3.5 Å.  For example, in a Fe<sub>4</sub>S<sub>4</sub> cluster the Fe...Fe distance is about 2.7 Å, so MIND -2 would be appropriate. A disulfide bond has a length of 2.03 Å so then MIND -1.5 could be used to resolve the sulfur atoms, however if DSUL is used for this purpose MIND -3.5 is required.


If heavy atoms can lie on special positions (as is the case with an iodide soak in a space group with twofold axes) the rejection of atoms on special positions should be switched off by giving the second MIND parameter as -0.1 (as in the above thaumatin example).
If heavy atoms can lie on special positions (as is the case with an iodide soak in a space group with twofold axes) the rejection of atoms on special positions should be switched off by giving the second MIND parameter as -0.1 .


=== Interpretation of results ===
=== Interpretation of results ===
Line 179: Line 179:


=== Full list of SHELXE options ( Version 2021/1; defaults in brackets) ===
=== Full list of SHELXE options ( Version 2021/1; defaults in brackets) ===
Full list of SHELXE options (defaults in brackets):
==================================================


  -aN - N cycles autotracing [off]
  -aN - N cycles autotracing [off]
Line 417: Line 412:


If these programs prove useful, you may wish to cite (and read!):<br>
If these programs prove useful, you may wish to cite (and read!):<br>
[http://scripts.iucr.org/cgi-bin/paper?sc5010 Sheldrick, G.M. (2008). "A short history of SHELX", ''Acta Crystallogr''. '''D64''', 112-122] [''Standard reference for all SHELX* programs''].<br>


Sheldrick, G.M., Hauptman, H.A., Weeks, C.M., Miller, R. & Usón, I. (2001). "Ab initio phasing". In ''International Tables for Crystallography'', Vol. F, Eds. Rossmann, M.G. & Arnold, E., IUCr and Kluwer Academic Publishers, Dordrecht pp. 333-351 [''Full background to the dual-space recycling used in SHELXD''].<br>
Sheldrick, G.M., Hauptman, H.A., Weeks, C.M., Miller, R. & Usón, I. (2001). "Ab initio phasing". In ''International Tables for Crystallography'', Vol. F, Eds. Rossmann, M.G. & Arnold, E., IUCr and Kluwer Academic Publishers, Dordrecht pp. 333-351 [''Full background to the dual-space recycling used in SHELXD''].<br>
Line 428: Line 421:
Nanao, M.H., Sheldrick, G.M. & Ravelli, R.B.G. (2005). "Improving radiation-damage substructures for RIP", ''Acta Crystallogr''. '''D61''', 1227-1237 [''Practical details of RIP phasing with SHELXC/D/E''].<br>
Nanao, M.H., Sheldrick, G.M. & Ravelli, R.B.G. (2005). "Improving radiation-damage substructures for RIP", ''Acta Crystallogr''. '''D61''', 1227-1237 [''Practical details of RIP phasing with SHELXC/D/E''].<br>


Uson, I., Stevenson, C.E.M., Lawson, D.M. & Sheldrick, G.M. (2007). "Structure determination of the O-methyltransferase NovP using the `free lunch algorithm' as implemented in SHELXE", ''Acta Crystallogr''. '''D63''', 1069-1074 [''Implementation of the FLA in SHELXE''].<br>
Usón, I., Stevenson, C.E.M., Lawson, D.M. & Sheldrick, G.M. (2007). "Structure determination of the O-methyltransferase NovP using the `free lunch algorithm' as implemented in SHELXE", ''Acta Crystallogr''. '''D63''', 1069-1074 [''Implementation of the FLA in SHELXE''].<br>
 
[http://scripts.iucr.org/cgi-bin/paper?sc5010 Sheldrick, G.M. (2008). "A short history of SHELX", ''Acta Crystallogr''. '''D64''', 112-122] [''Standard reference for all SHELX* programs''].<br>


[http://dx.doi.org/10.1107/S0907444909038360 Sheldrick, G.M. (2010). "Experimental phasing with SHELXC/D/E: combining chain tracing with density modification", ''Acta Cryst'' '''D66''', 479-485.]  
[http://dx.doi.org/10.1107/S0907444909038360 Sheldrick, G.M. (2010). "Experimental phasing with SHELXC/D/E: combining chain tracing with density modification", ''Acta Cryst'' '''D66''', 479-485.]  


[https://doi.org/10.1107/S0907444913027534 A. Thorn and Sheldrick, G.M. (2013) Extending molecular-replacement solutions with SHELXE. ''Acta Cryst'' '''D69''', 2251-2256.]
[https://doi.org/10.1107/S0907444913027534 A. Thorn and Sheldrick, G.M. (2013). Extending molecular-replacement solutions with SHELXE. ''Acta Cryst'' '''D69''', 2251-2256.]
 
[https://journals.iucr.org/d/issues/2018/02/00/ba5271/ba5271.pdf Usón, I. & Sheldrick, G. M. (2018). An introduction to experimental phasing of macromolecules illustrated by SHELX; new autotracing features. ''Acta Cryst.'' '''D74''', 106-116.]
<br>
<br>
See also the [http://shelx.uni-goettingen.de/ SHELX homepage]
See also the [http://shelx.uni-goettingen.de/ SHELX homepage]
<br>
<br>
1,334

edits