double precision vdwcompon(ntyp,ntyp),vdw2compon(ntyp),
     & becompon(ntyp),sccompon(ntyp),torcompon(ntyp,ntyp),
     & sccorcompon(ntyp,ntyp),tordcompon(ntyp)
      common /ecomponents/ vdwcompon,vdw2compon,becompon,sccompon,
     & torcompon,sccorcompon,tordcompon