C     IBUFEXCH is the size of the exchange buffers used for the
C     halo exchanges. The current size should be more than sufficient
C     for the forseeable future.
C
C     IBUFEXCH would need to be increased if you ever receive an error 
C     from the MPI library indicating that the recieive buffer is too small.
C
C     You should do a "make clean" if you increase IBUFEXCH.
C
C     Jim Tuccillo Feb 2001
C 
      INTEGER IBUFEXCH
      PARAMETER ( IBUFEXCH = 2500000 )