*deck potinf
      function potinf ( r, j )
c
c >>> potinf -- computes the unperturbed diatomic potential
c
c --- on entry the calling routine supplies --
c
c     r -- the internuclear distance
c     j -- the molecular angular momentum
c
c --- on exit the routine returns --
c
c     potinf -- the value of the potential
c
c --- NOTE -- this version is for the H2 (or D2) molecule in the
c             t-mu + D2 program.  It receives information also through
c             the common block POTPAR in the variables VBASE,EMASS,UNITS
c
      implicit real*8 (a-h,o-z)
      common / potpar / vbase, emass, units
      common / syscom / twomus, twomum
ctest      common / eqd / evibo, evibh
ctest      common / bas3dc / nho, hscale, rzero
c
      data ncall / 0 /
c
      ncall = ncall + 1
      if ( ncall .gt. 1 ) go to 10
      vbase = -4.74764d0
      emass = 232.51d0
      units = 27.2116d0

   10 continue
c
      potinf = vh2(r) - vbase
c
c     the next "line" would be necessary if the input vibrational
c             basis did not have the centrigual stretching potential
c             in it.
cline      potinf = potinf + j*(j+1)/(twomum*r**2)
c
c     the "test" lines would be appropriate if the program
c           were to use a harmonic vibrational basis
ctest      potinf = evibo*(r - rzero)**2 + j*(j+1)/(twomum*r**2)
c
      return
      end