Author: Dave Case
Date: 9/25/91

PROBLEM: The documentation states that constraints read in the PARM
         program must be terminated with a blank card, but the program
         actually requires a card with 4 zero integers and two zero
         floats

SYMPTOM: PARM exits with an error message; no incorrect results would
         be obtained, but users would be confused.

FIX:     Use the RFREE routines to read the constraints, since these
         interpret blanks as zeroes.

rconst.f:

+ added line
- deleted
! changed

*** old rconst.f	
--- new rconst.f
***************
*** 54,59 ****
--- 54,61 ----
  c     Rev A mod:  use double temps
  c                 also use doubles for arithmetic on parameters
        double precision conv, req1, conk
+       dimension ifld(7),ihol(1),ivar(4),fvar(2)
+       data ifld /4*2,2*3,0/
  c
  c     --- get PI / 180. ---
        CONV = 4.0d0*ATAN(1.0d0)/180.0d0
***************
*** 74,85 ****
        i = 0
     51 continue
        i = i + 1
- *     DO 51 I = 1,7500 ! this is supposed to be a do while (i1 .ne. 0)
  c
! c   ---dac change 7/90: allow free format for constraint input
  c
! c     READ(IN,52,end=1000) I1,J1,K1,L1,REQ1,CONK
!       READ(IN,*,end=1000) I1,J1,K1,L1,REQ1,CONK
        IF(I1.LE.0) GO TO 53
        IF(J1.LE.0) then
             WRITE(IOUT,54) I
--- 76,94 ----
        i = 0
     51 continue
        i = i + 1
  c
! c     --- call to rfree mimics the following free-format read,
! c         but interprets blanks as zero:
  c
! c     READ(IN,*) I1,J1,K1,L1,REQ1,CONK
! c
!       call rfree(ifld,ihol,ivar,fvar,IN,6)
!       i1 = ivar(1)
!       j1 = ivar(2)
!       k1 = ivar(3)
!       l1 = ivar(4)
!       req1 = fvar(1)
!       conk = fvar(2)
        IF(I1.LE.0) GO TO 53
        IF(J1.LE.0) then
             WRITE(IOUT,54) I
***************
*** 160,173 ****
  C     ----- ADD 180. TO CONVVERT 1+COS TO 1-COS IN DIHEDRAL SECTION ----
  C
        PHASE(MPTRA) = CONV*(REQ1+180.0d0)
- *  51 CONTINUE
        go to 51
     53 CONTINUE
        RETURN
-  1000 continue
-       write(iout,'(/2x,a,a)') 'FATAL: End of file reached while',
-      +      ' reading constraints.  Needs blank card at end.'
-       call mexit(iout, 1)
     52 FORMAT(4I5,2F10.2)
     54 FORMAT(/2X,'FATAL: Constraint card number ',i5,' is bungled.')
   9000 format(/5x,'Internal Coordinate Constraints:',/5x,'Type',5x,
--- 169,177 ----