Author:  Dave Case
Date:  9/25/91

PROBLEM:   It is possible to prepare constraint input to SANDER that
           has too many equivalence groups in it.  Version 4.0 uses
           a guess at the number of groups, but this can be too small.

SYMPTOM:   SANDER exits with an error message if too many groups are
           used.  No incorrect results would be obtained, but users
           might not find it easy to figure out which routines need
           to be changed to increase the number of allowed groups.

FIX:       In src/sander/restal.f, count the number of groups actually
           used prior to calling the memory allocation routines.  This
           allows an arbitary number of groups to be present, and
           doesn't waste any space.

++++nmrcal.f:

*** old nmrcal.f
--- new nmrcal.f
***************
*** 192,200 ****
  C    MAXWT  :  The maximum allowable number of weight-change cards.
  C    MAXGRP  : The maximum number of ranges of atoms which can be stored
  C              as group information (only needed when using group center-of-mass
! C              coordinates in distance restraints). By default, this value
! C              is set to MAXRST. If a non-zero value of MXGRP is passed
! C              to RESTLX, this value will be used as MAXGRP.
  C    INTREQ :  The amount of integer work array (IWORK) storage required.
  C    IRLREQ :  The amount of real work arary (WORK) storage required.
  C
--- 192,202 ----
  C    MAXWT  :  The maximum allowable number of weight-change cards.
  C    MAXGRP  : The maximum number of ranges of atoms which can be stored
  C              as group information (only needed when using group center-of-mass
! C              coordinates in distance restraints). This value is 
! C              computed in the initial call to RESTAL.
! C              [If a non-zero value of MXGRP is passed
! C              to RESTLX, this value will be used as MAXGRP; this
! C              option is not used in the present code.]
  C    INTREQ :  The amount of integer work array (IWORK) storage required.
  C    IRLREQ :  The amount of real work arary (WORK) storage required.
  C
***************
*** 395,404 ****
  C specify lots of unnecessary stuff in the calling list:
  C
        ENTRY RESTLX(IN,ITOTST,MXGRP,INTREQ,IRLREQ,DTT,IOUT,IERR)
!           CALL RESTAL(ISCOP1,IN,ITOTST,ICHGWT,NMRNUM,ITMAV,IOUT,IERR)
            MAXRST = NMRNUM + 1 + 5*IERR
            MAXWT = ICHGWT + 1 + 5*IERR
!           MAXGRP = MAX(MAXRST,100)
            IF (MXGRP.GT.0) MAXGRP = MXGRP
            ITIMAV = ITMAV
            IF (ITOTST.EQ.0) ITIMAV = 0
--- 397,407 ----
  C specify lots of unnecessary stuff in the calling list:
  C
        ENTRY RESTLX(IN,ITOTST,MXGRP,INTREQ,IRLREQ,DTT,IOUT,IERR)
!           CALL RESTAL(ISCOP1,IN,ITOTST,ICHGWT,NMRNUM,ITMAV,IOUT,IERR,
!      *        NUMGRP)
            MAXRST = NMRNUM + 1 + 5*IERR
            MAXWT = ICHGWT + 1 + 5*IERR
!           MAXGRP = NUMGRP + 1
            IF (MXGRP.GT.0) MAXGRP = MXGRP
            ITIMAV = ITMAV
            IF (ITOTST.EQ.0) ITIMAV = 0

++++restal.f:
*** old restal.f
--- new restal.f
***************
*** 16,22 ****
  C************************************************************************
  C
        SUBROUTINE RESTAL(ISCOP1,IN,ITOTST,ICHGWT,NMRNUM,ITIMAV,
!      *                  IOUT,IERR)
  C
  C Subroutine RESTraint Allocation
  C
--- 16,22 ----
  C************************************************************************
  C
        SUBROUTINE RESTAL(ISCOP1,IN,ITOTST,ICHGWT,NMRNUM,ITIMAV,
!      *                  IOUT,IERR,NUMGRP)
  C
  C Subroutine RESTraint Allocation
  C
***************
*** 43,48 ****
--- 43,49 ----
  C OUTPUT:
  C      ICHGWT : Number of change parameters read.
  C      NMRNUM : The total number of NMR restraints defined.
+ C      NUMGRP : The total number of NMR groups defined.
  C      ITIMAV : = 1 If any time-averaged restraints were requested.
  C               = 0 otherwise.
  C        IERR : Returned as 0 if no problems reading input. Returned as
***************
*** 125,130 ****
--- 126,132 ----
  C
        ICHGWT = 0
        NMRNUM = 0
+       NUMGRP = 0
        IBAVER = 0
        IAAVER = 0
        IPAVER = 0
***************
*** 326,332 ****
  C
  C If IAT1=0, assume this a blank line & the last restraint has been read.
  C
!           NMRNUM = NMRNUM + 1
            IF (IAT1.EQ.0) GO TO 100
     30 CONTINUE
  C
--- 328,348 ----
  C
  C If IAT1=0, assume this a blank line & the last restraint has been read.
  C
!           if (iat1.lt.0) then
!             numgrp = numgrp + 1
!             do 31 ig=2,MAXIGR
!               if (igr1(ig).eq.0) go to 32
!               if (igr1(ig).ne.igr1(ig-1)+1) numgrp = numgrp + 1
!    31       continue
!           end if
!    32     if (iat2.lt.0) then
!             numgrp = numgrp + 1
!             do 33 ig=2,MAXIGR
!               if (igr2(ig).eq.0) go to 34
!               if (igr2(ig).ne.igr2(ig-1)+1) numgrp = numgrp + 1
!    33       continue
!           end if
!    34     NMRNUM = NMRNUM + 1
            IF (IAT1.EQ.0) GO TO 100
     30 CONTINUE
  C
***************
*** 334,339 ****
--- 350,356 ----
    100 CONTINUE
  C
        IF (IOTHRD.NE.0) CALL OPNMRG(REDIR(3),IIN,3,IOUT,IERR)
+ c     write(6,*) 'returning from restal. nmrnum,numgrp=',nmrnum,numgrp
        RETURN
  C
  C Errors: