********> bugfix.40
Correction Author: David A. Pearlman
Correction Date: 5/11/92  

Programs: GIBBS

Severity: slight

Problem: 

       The second value in the total range of lambda values printed in the
       summary section of the MICSTAT file might be incorrect in the
       case where statistics are being "dumped" to the MICSTAT file
       frequently. This is unlikely to occur if the default value of
       NDMPMC (0) has been used, as is typical. 

       *In any case, the ONLY incorrect value in the MICSTAT file would
       be this single second value in the lambda range, i.e.*

                                  *SUMMARY*
                                                   FREE ENERGIES
                                    # STEPS       DATA COLLECTION
                         AVE     TOT AVE  AVE    TOTAL       TOTAL
 WIND  STEPS LAMBDA    dLAMBDA    NR  EQ  COLL   FORWARD    REVERSE
    5     20 1.00-0.00 0.080000   0     2     2    -2.5793     3.2463
                  ^^^^
                    \ 
                      only this value would be affected. NO other
       values in the file would be incorrect.

Affects: 

       The value shown might be incorrect. A likely value would be 0.00
       when the simulation did not end at lambda=0. All other lambda and
       free energy information in the file is correct.

Cause: 

       The summary print stage consists of dumping any remaining statistics,
       followed by printing the summary. The logic being used assumed
       that at least one window's worth of statistics would be printed
       before the summary print. If this was not the case, the incorrect
       lambda value noted above could result.

Fix:  Make the following changes (see 0README for a description of context 
      diffs)

---To routine MICST in src/gibbs/micst.f-------------------------------------

*** OLD micst.f
--- NEW micst.f
***************
*** 99,105 ****
  C
        DATA SMALL/1.0D-9/
        DATA BLANK/'          '/
!       SAVE IONCE,SMALL,BLANK,IWNDNO
        SAVE /MICST0/,/MICST1/
  C
        IF (NDUMP.LT.0) RETURN
--- 99,105 ----
  C
        DATA SMALL/1.0D-9/
        DATA BLANK/'          '/
!       SAVE IONCE,SMALL,BLANK,IWNDNO,ALMLST
        SAVE /MICST0/,/MICST1/
  C
        IF (NDUMP.LT.0) RETURN
***************
*** 264,269 ****
--- 264,270 ----
   1210 CONTINUE
  C
        NTOT(0) = NTOT(NCOUNT-1)
+       ALMLST = ALAM0(IEND)
  c     NWIND = NWIND + NCOUNT-1
        NWIND = IWNDNO
        NCOUNT = 1
***************
*** 282,288 ****
        IF (IWNDNO.EQ.0) IWNDNO = 1
        RL = FLOAT(IWNDNO)
        WRITE(IOUT,1303)
!       WRITE(IOUT,1304) IWNDNO,NTOT(IEND),ALM1,ALAM0(IEND),DLTOT/RL,
       *                     NRTOT,NINT(FLOAT(NEQTOT)/RL),
       *                     NINT(FLOAT(NCOTOT)/RL),
       *                     AFCTOT,ARCTOT
--- 283,289 ----
        IF (IWNDNO.EQ.0) IWNDNO = 1
        RL = FLOAT(IWNDNO)
        WRITE(IOUT,1303)
!       WRITE(IOUT,1304) IWNDNO,NTOT(IEND),ALM1,ALMLST,DLTOT/RL,
       *                     NRTOT,NINT(FLOAT(NEQTOT)/RL),
       *                     NINT(FLOAT(NCOTOT)/RL),
       *                     AFCTOT,ARCTOT

------------------------------------------------------------------------------
------------------------------------------------------------------------------


Temporary workarounds: 

     The error is trivial, and can easily be ignored.

Routines affected:

     GIBBS   Routine MICST in  .../amber4/src/gibbs/micst.f