help me out

Zhi Chen chen at HIS.SB.FSU.EDU
Mon Jun 30 13:17:47 EST 1997


I'm trying to evaluate the phase difference between two sets of
reflections from initial and refined models. No matter how I tried,
I always got $DPHI=0.0 !!! I cannot see why though it is impossible.
Please help me out. The X-PLOR input file is as follows. I'm using 
X-PLOR V3.843

[Input file]

set echo=off end

topology @TOPPAR:tophcsdx.pro end
parameter @TOPPAR:parhcsdx.pro end

structure @prot.psf end
coordinates @prot.pdb

evaluate ( $SG="P2(1)2(1)2(1)" )

xrefine

  @XTALLIB:spacegroup.lib
  @XTALLIB:scatter.lib
  a=61.76 b=40.73 c=26.74 alpha=90.0 beta=90.0 gamma=90.0

  resolution 10.0 2.0
  method=FFT
  lookup=false

  fft 
    grid=0.333
    memory=2000000
  end 

end

xrefine
  reflection @prot.fob end
  selection=( known and not hydrogen )

  update
  print phase
  display $dphi
end

stop


[part of log file]

 XREFINE>  update 
 XREDUC: mapping reflections into standard asymmetric unit.
 XREFIN: selected reflections will be sorted by index.
 XRTEST: number of selected reflections    3355
 XRFILL: #scatt.=  558 #anomalous=  0 #special pos.=  0 occupancies=1
 XFFT: using grid [ 96, 64, 40] and sublattice [ 96( 97), 64( 65), 40]
 XREFINE>  print phase 
 XRTEST: number of selected reflections    3355
 PRRPHA:  optimum Fobs/Fcalc scale =   0.138
 {{  (* resol.-range  #reflect.  weig. phase-diff.  Accum.*)
   {      3.98, 17.00,        0,       0.0000,  0.0000  }, 
   {      3.17,  3.98,        0,       0.0000,  0.0000  }, 
   {      2.77,  3.17,        0,       0.0000,  0.0000  }, 
   {      2.52,  2.77,        0,       0.0000,  0.0000  }, 
   {      2.34,  2.52,        0,       0.0000,  0.0000  }, 
   {      2.20,  2.34,        0,       0.0000,  0.0000  }, 
   {      2.09,  2.20,        0,       0.0000,  0.0000  }, 
   {      2.00,  2.09,        0,       0.0000,  0.0000  }},
 XREFINE>  display $dphi 
0
 XREFINE>end 
 X-PLOR> 
 X-PLOR>stop 

[head of reflection file]

 NREFlection=      3788
 ANOMalous=FALSe { equiv. to HERMitian=TRUE}
 DECLare NAME=FOBS         DOMAin=RECIprocal   TYPE=COMP END
 DECLare NAME=SIGMA        DOMAin=RECIprocal   TYPE=REAL END
 INDE     0    0    2 FOBS=    40.400     0.000 SIGMA=     0.300
 INDE     0    0    4 FOBS=    36.500     0.000 SIGMA=     0.300
 INDE     0    0   10 FOBS=    11.300     0.000 SIGMA=     1.300
 INDE     0    1    3 FOBS=    60.000     0.000 SIGMA=     0.500
 INDE     0    1    4 FOBS=    31.500     0.000 SIGMA=     0.300
 INDE     0    1    6 FOBS=    21.000     0.000 SIGMA=     0.200
 INDE     0    1    8 FOBS=    49.300     0.000 SIGMA=     0.200
.
.
.
-- 



=============================================================
# Zhi Chen		  Institute of Molecular Biophysics #
# E-mail: chen at his.sb.fsu.edu				    #
=============================================================




More information about the X-plor mailing list