function gvdw(il,ilist,id)
c     ==========================
c
c     evaluation of the Van der Waals broadening parameter
c
c     currently, two possibilities, determined by the value of the parameter
c     ivdwli(ilist) - the mode of evaluation is the same for the whole line list
c       = 0 - standard expression
c       > 0 - evaluation using EXOMOL data, assuming breadening by H2 and He
c
      INCLUDE 'PARAMS.FOR'
      INCLUDE 'MODELP.FOR'
      INCLUDE 'LINDAT.FOR'
      COMMON/PRFQUA/DOPA1(MATOM,MDEPTH),VDWC(MDEPTH)
c
c     clasical, original expression
c
      if(ivdwli(ilist).eq.0) then
         gvdw=gwm(il,ilist)*vdwc(id)
         return
      end if
c
c     EXOMOL form - broadening by H2 and He
c
c     con= 1.e-6*c*k
      con=4.1388e-12
      t=temp(id)
      anhe=rrr(id,1,2)
      gvdw=con*t*((296./t)**gexph2(il,ilist)*gvdwh2(il,ilist)*anh2(id)+
     *            (296./t)**gexphe(il,ilist)*gvdwhe(il,ilist)*anhe)
      return
      end