c
c###################################################################
c
      subroutine jborn2(pe, pcf, kncf, pfit, kermsg)
c
c     this is a subroutine to calculate cross sections (cm[2])
c     versus energy (ev) using a formula based on a semiempirical
c     modification of the bethe-born formula.
c     (this expression is identical to that used in jborn1, however,
c      to be able to uniquely identify the different choices of
c      weighting seperate routines have been kept, see
c      doc=h-he-plasma)
c
c     pcf is the coefficient data array, where
c
c     pcf(1) =   the threshold energy for the reaction (ev)
c
c     pcf(2) =    the minimum energy for the application of the
c                 semiempirical formulae.
c
c     pcf(3)  =   coefficient a
c
c     pcf(4)  =   coefficient n
c
c     pe = collision energy in ev
c
c     kermsg = blank if no errors
c
c     pfit = cross section in cm[2]
c
c     written by j. j. smith , iaea atomic and molecular data unit
c
c------------------------------------------------------------------------
c
      double precision pe, pcf, pfit
      dimension pcf(11)
      character*(*) kermsg

      eth=pcf(1)
      emin = pcf(2)
      a=pcf(3)
      n=pcf(4)
      an=n
      if(pe .ge. eth) then
        kermsg = ' '
      else
        kermsg = 'energy is below threshold for reaction in jborn2'
        return
      endif
c
      pfit = a*((eth/pe)**an) *dlog(pe/eth)
  100 return
c
      end