********> bugfix.27
Correction Author: David A. Pearlman
Correction Date: 1/2/92

Programs: sander

Severity: moderate

Problem:  Line 15 of the section ZERO input (minimization control flags)
     was only being read if imin=1 (line 2). This is inconsistent with
     the scheme for program minmd (where line 15 is always read), and
     inconsistent with the documentation.

     This problem only affects formatted input (numbers in columns).
     If you are using the &cntrl namelist to specify section ZERO input,
     the problem would not be encountered.

     
Affects: If a simulation is run where the following conditions are met:

        1) MD run (not minimization; i.e. imin=0);
        2) No restraint or weight change instructions are read (NMRMAX=0);
        3) Additional group input reads following the standard input
           are required (either position restraints or belly);


      then including line 15, seemingly correct according to the manual,
      will cause a misread.


Cause: A check on the value of imin was being made before reading line 15.
     This is not consistent with MINMD or with the manual.

Fix: In routine MDREAD in src/sander/mdread.f

     make the following change:

      --old line: 

      if (imin.ne.0) read(5,9043) maxcyc,ncyc,ntmin,dx0,dxm,dele,drms

      --new line: 

      read(5,9043) maxcyc,ncyc,ntmin,dx0,dxm,dele,drms


Temporary workarounds: When running md with sander (imin=0), do not include
     line 15.

Routines affected:

     SANDER:  Routine MDREAD in file .../amber4/src/sander/mdread.f