reduction of van der Waals forces

Hi CCLers,
 I wonder if it is possible in InsightII to gradually reduce the van der
 Waals forces in an optimization job.
 I have an NMR structure of a chunk of RNA with a ligand, but the structure
 has some bad contacts, hence I have problems docking the ligand in its
 Any suggestions are glady appreciated.
 Thanks a lot in advance
 Carsten Detering
 University of Washington
 Seattle, WA 98195
 email detering (+ at +)