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[ccp4bb]: pvdw function



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Dear all !

i am refining the structure of complex in which the ligand
lies across the
symmetry axis such that half portion of the ligand is generated upon
itself due to symmetry (only half the molecule of ligand lies in one
asymmetric unit, the other identicel half belongs to the symmetry realted
molecule).
i have generated only half the molecule but during refinement, the two
halves are considered as short contacts by the programm and any further
refinement keeps pushing them apart.
i decided to fix the ligand molecule during refinement and 
put off pvdw energy function only between the halves of the
ligand molecule.
that should effectively lower my Rf and Rcryst values , shouldn'it ?
but my refinement seems to follow to similar Rf and Rcryst with or without
pvdw function put to zero.

i am using CNS at present, 
 Any suggestions regarding fixing the problem in either CNS or CCP4 are
welcome!

thanx everybody! 

Goel M.