Hi Eiso Thanks for the quick reply. I made a typo in the post. We did set AVERAGE=CENTRE but apparently xplor forces SUM when you use OR in the ASSIGN statement. So the question is how to get around this.
Kaare On 11/2/11 1:53 PM, "Eiso AB" <eab at zobio.com> wrote: > Kaare Teilum wrote: >> Dear Charles / all >> >> I have a question concerning an atom selection in a special case. I need to >> make >> a restraint between a proton and the exact center of an aromatic ring (in >> this >> case the 6-ring in a tryptophan indole). So far, I've tried to define it as >> an >> NOE in the following way: >> >> ASSIGN (RESID 19 AND NAME HE3) ( (RESID 20 AND NAME CE2) or (RESID 20 AND >> NAME >> CZ3) ) 2.5 1.0 1.0 >> >> and setting avetype to SUM for this restraint. It was evident, that the 19 >> HE3 >> either was restrained to CE2 OR CZ3 and not in between them. How should I >> write >> the NOE in order to select the center of the tryptophan ring - is this >> possible? >> > > why 'SUM' and not 'CENTER' ? > > from > http://nmr.cit.nih.gov/xplor-nih/doc/current/xplor/node379.html#5077 : > > ''' > For AVERage=CENTer, the distance between selected sets of atoms is set to the > difference between the geometric centers of the atoms, > \begin{displaymath} R= (r^{1}_{center} - r^{2}_{center}) \end{displaymath} > ''' > > > goodluck, Eiso > > >
