[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [ccp4bb]: dodgy indexing
*** For details on how to be removed from this list visit the ***
*** CCP4 home page http://www.dl.ac.uk/CCP/CCP4/main.html ***
Sorry,
It should be "smallest reciprocal cell constant"
delta phi = ( longest reciprocal cell / d*min)(180/pi) - mosaicity
^^^^^^^
smallest
__________________________________________________________________________
(_) LAB ADDRESS:: : HOSTEL ADDRESS:: (_)
| | : | |
| | Gosu Ramachandraiah : Gosu Ramachandraiah | |
| | Prof.M.Vijayan's Lab : Research Scholar | |
| | Molecular Biophysics Unit : M Block, Room # 31 | |
| | Indian Institute of Science : Indian Institute of Science | |
| | Bangalore 560012, INDIA : Bangalore-560012, INDIA | |
| | Ph :91-80-3092389 : Ph :91-80-3092453 | |
| | Fax :91-80-3600535 : | |
| | email:gosu@mbu.iisc.ernet.in : | |
| |__________________________________:___________________________________| |
(_) (_)
On Wed, 28 Feb 2001, Gosu RamaChandraiah wrote:
>
> hi,
>
> In denzo, mosaicity is defined as the smallest angle through which
> the crystal can rotate about an axis or combination of axes while a
> reflection is still observed.
>
> From this definition, we can extend our logic for single crystal
> oscillation photography...
>
> delta phi = ( longest reciprocal cell / d*min)(180/pi) - mosaicity
>
>
> mosaicity should be smaller than the first term so that delta
> phi remains a positive quantity.
>
> If crystal is highly mosaic, oscillation angle(delta phi)
> should have been very small while collecting the data. Or else at the time
> of processing one has to select a shell of reflections to start indexing
> from equation mentioned above.
>
> With regards
> GOSU
>
> __________________________________________________________________________
> (_) LAB ADDRESS:: : HOSTEL ADDRESS:: (_)
> | | : | |
> | | Gosu Ramachandraiah : Gosu Ramachandraiah | |
> | | Prof.M.Vijayan's Lab : Research Scholar | |
> | | Molecular Biophysics Unit : M Block, Room # 31 | |
> | | Indian Institute of Science : Indian Institute of Science | |
> | | Bangalore 560012, INDIA : Bangalore-560012, INDIA | |
> | | Ph :91-80-3092389 : Ph :91-80-3092453 | |
> | | Fax :91-80-3600535 : | |
> | | email:gosu@mbu.iisc.ernet.in : | |
> | |__________________________________:___________________________________| |
> (_) (_)
>
>
>
>
> On Tue, 27 Feb 2001, Lauris Kemp wrote:
>
> > *** For details on how to be removed from this list visit the ***
> > *** CCP4 home page http://www.dl.ac.uk/CCP/CCP4/main.html ***
> >
> > Hello
> > I'm trying to index a data set with denzo. The problem is with
> > mosaicity-it looks about 1 but at this value it misses out some low
> > resolution spots and seems to overfit for the number of spots at high
> > resolution. Thought it might be misindexed but did a direct beam shot
> > and the beam values look about right. It manages to autoindex it fine
> > and the chi values are also fine.
> > Lauris
> >
>
>