I hate scalepack for this - it only lists absences and not the other axial reflections so you dont get a comparative scale.. SCALA is much more informative..
And it is always a bit dodgy basing the choice of space group on 3 absences alone, However after that gripe, indeed all 3 have I <<< 3SigI so the evidence is for P4(2) 22 In general you only think a reflection is present if it is > 4 or 5 Sig but I base all that partly on the relative size of the 00 2l, and 00 2l+1 sets. Eleanor 劉家欣(NTHU) wrote: > Dear Prof. Dodson: > > Thank you for your kindly suggestions. > Actually, the sg we predicted was P4222. However, the systematic > absence was > showed alone 00l in the log file(In below). > Is ant conflict on that? > Thanks again I appreciated. > > Sincerely, > > > jaishin > > Intensities of systematic absences > h k l Intensity Sigma I/Sigma > > 0 0 17 -5.3 21.3 -0.2 > 0 0 19 7.2 24.9 0.3 > 0 0 21 -13.4 22.0 -0.6 > > ----- Original Message ----- From: "Eleanor Dodson" > <[EMAIL PROTECTED]> > To: ""劉家欣(NTHU)"" <[EMAIL PROTECTED]> > Cc: <[email protected]> > Sent: Thursday, December 11, 2008 5:41 PM > Subject: Re: [ccp4bb] About system absence in P4222? > > >> 劉家欣(NTHU) wrote: >>> Dear All: >>> >>> We have a crystl with P4222 sg. >>> All statistics look fine. >>> However, there is a system absense in l axis. >>> Any body have experiences on that? >>> Any suggestions would be high appreciated. >>> >>> jaishin >>> >> can you give more details, eg all reflections along the particular >> axis.. >> Things like ice rings or overlapping intensity from a next neighbour >> getting integrated inapropriately can cause anomalies.. >> Eleanor >> > > >
