Converting a CCP4 MTZ reflection file

There are two programs which can be used to convert CCP4 MTZ format reflection files to CNS format (both programs are part of CCP4 version 3.5):

• SFTOOLS: This can read an MTZ file then write it back out in CNS format. All items will be correctly converted. However, the header information from the CNS file is not written. This must be added manually. The header for a file with experimental phase information should look something like this:

   NREFlection=           1400
   ANOMalous=TRUE { equiv. to HERMitian=FALSe}
   DECLare NAME=FOBS        DOMAin=RECIprocal   TYPE=COMP END
   DECLare NAME=SIGMA       DOMAin=RECIprocal   TYPE=REAL END
   DECLare NAME=PA          DOMAin=RECIprocal   TYPE=REAL END
   DECLare NAME=PB          DOMAin=RECIprocal   TYPE=REAL END
   DECLare NAME=PC          DOMAin=RECIprocal   TYPE=REAL END
   DECLare NAME=PD          DOMAin=RECIprocal   TYPE=REAL END
   GROUp TYPE=HL
     OBJEct=PA
     OBJEct=PB
     OBJEct=PC
     OBJEct=PD
   END
   INDE     0    4    2 FOBS=     677.8       0.0 SIGMA=     19.40
                        PA=    -0.486 PB=     0.000 PC=     0.000 PD=     0.000
  

  Note that the grouping of the HL coefficients is essential in order that remapping of reflections to a different asymmetric unit is performed correctly.
• mtz2various: This can read an MTZ file and write out a complete CNS reflection file. An example script is:

  mtz2various HKLIN infile HKLOUT outfile << EOF
  RESOLUTION 10000 2
  OUTPUT CNS
  EXCLUDE SIGP 0.001   # to exclude unmeasured refl.
  LABIN FP=Fnat SIGFP=SIGnat PHIB=PHI FOM=FOMM HLA=HLA HLB=HLB HLC=HLC HLD=HLD
  END
  EOF
  

  If you have anomalous data as F and deltaF:

  # Convert MTZ file with anomalous data as F and deltaF to CNS format.
  # F(+h +k +l) and F(-h -k -l) are reconstructed from FP and DP.
  
  mtz2various hklin file.mtz HKLOUT file.hkl  <<+
  LABIN  FP=F SIGFP=SIGF DP=DANO SIGDP=SIGDANO
  OUTPUT CNS
  END
  +
  

  If you have anomalous data as F(+) and F(-):

  # Convert MTZ file with anomalous data as F(+) and F(-) to CNS format.
  
  mtz2various hklin file.mtz HKLOUT file.hkl  <<+
  LABIN  F(+)=F(+) SIGF(+)=SIGF(+) F(-)=F(-) SIGF(-)=SIGF(-)
  OUTPUT CNS
  END
  +