***********************************************************************
*
*     H4 PES Fit to the 6101 ab initio points of Boothroyd et al.
*     J. Chem. Phys. 95, 4331 (1991)
*
*     See A. Aguado, C. Suarez and M. Paniagua. J. Chem. Phys. Accepted
*
************************************************************************
*     TEST MAIN PROGRAM, call function H4FINAL to obtain the true PES.
      PROGRAM H4JCP
      IMPLICIT REAL * 8 (A-H,O-Z)
      READ(5,*) NPUN,NFUN
***********************************************************************
*     IF (NFUN.GT.0) obtain the H4 energy from H4FINAL, given the
*                    six internuclear distances. Note that you must fix
*                    the atoms A,B,C,D, before using the function
*                    H4FINAL(RAB,RAC,RBC,RAD,RBD,RCD), giving the
*                    distances in that order. Note also that the six
*                    internuclear distances are not independent
*                    variables (if you want independent variables use,
*                    e.g., the H4INTC or your own set by computing
*                    the six internuclear distances, and then calling
*                    to H4FINAL).
*
*     IF (NFUN.LE.0) obtain the H4 energy from H4INTC, given the
*                    internal coordinates as defined in the JCP paper.
***********************************************************************
      write(6,5)
   5  format(1x,'NABS     AB INITIO   FITTED ENERGY')
      rms = 0.d0
      DO 10 I=1,NPUN
         IF(NFUN.GT.0) THEN
            READ(5,*) nabs,RAB,RAC,RBC,RAD,RBD,RCD,ENER
            ENER2=H4FINAL(RAB,RAC,RBC,RAD,RBD,RCD)
         ELSE
            READ(5,*) nabs,R,RAB,RCD,ALFA,BETA,GAMA,ener
            ENER2=H4INTC(R,RAB,RCD,ALFA,BETA,GAMA)
         endif
         rms = rms + (ener-ener2)**2
  10     write(6,20) nabs,ener,ener2
* 10     continue
  20  format(1x,i5,2(1x,f12.6))
      rms=dsqrt(rms/npun)
      write(6,30) npun,rms,rms*627.5d0
  30  format(1x,'The rms in ',i4,' points is ',f12.6,' a.u. or ',f12.6,
     ,' kcal/mol')
      STOP
      END