c
c###################################################################
c
      subroutine aljan1(pet, pcf, kncf, pfit, kermsg)
c
c     this is a subroutine to calculate cross sections (cm[2])
c     versus energy (ev) or electron impact reaction rate
c     coefficient (cm[3]/s) versus electron tempreature (ev).
c     using the log natural polynomial fit of janev et al.
c
c     these fits are valid only between the limits emin and emax,
c     which are parameters pcf(1) and pcf(2) in the entry data field
c     the parameters pcf(3-11) are the coeficients for the fiiting
c     formula.
c
c     pet = 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 pet, pcf, pfit
      double precision emin, emax, aloge1, aloge, xjan, xcon
      dimension pcf(11)
      character*(*) kermsg

      emin=pcf(1)
      emax = pcf(2)
      if(pet .ge. emin .and. pet .le. emax) then
        kermsg = ' '
      else
        kermsg = 'outside range of fit in aljanxs'
        return
      endif
c
c     calculate natutral log polynomial
c
      aloge1 = dlog(pet)
      aloge = aloge1
      xjan = pcf(3)
      do 10 i=4,11
      xcon = pcf(i)*aloge
      xjan = xjan + xcon
   10 aloge=aloge * aloge1
      pfit = dexp(xjan)
  100 return
c
      end