c------------------------------------------------------------------------------
c     Parameters and data structures for program AHB1
c------------------------------------------------------------------------------
c     Written by A. W. Sandvik (asandvik@abo.fi), Åbo Akademi University.
c     Last modifeid: Sept. 1, 2002.
c------------------------------------------------------------------------------

      IMPLICIT NONE

      INTEGER dd
      INTEGER nx
      INTEGER bm
      INTEGER nn
      INTEGER nb
      INTEGER mm
      INTEGER ll

c==============================================================================
c     USER-ADJUSTABLE LATTICE SIZE PARAMETERS
c==============================================================================
      PARAMETER (dd=2)     ! number of dimensions
      PARAMETER (nx=8)     ! linear size (length)
      PARAMETER (bm=32)    ! highest (appr.) inverse temperature J/T
c==============================================================================
c     Other parameters:
c------------------------------------------------------------------------------
c     nn = number of sites
c     nb = number of bonds
c     mm = maximum order of series expansion
c     ll = maximum length of operator strings including 0-elements
c------------------------------------------------------------------------------
      PARAMETER (nn=nx**dd)
      PARAMETER (nb=dd*nn)
      PARAMETER (mm=(4*nb*bm)/5)
      PARAMETER (ll=(5*mm)/4)

c------------------------------------------------------------------------------
c     Frequently used variable and data structures
c------------------------------------------------------------------------------
c     l   = expansion cut-off
c     nh  = number of non-0 elements in the operator string 
c     str = operator string
c     bst = list of site-pairs conneted by all the interaction bonds
c     spn = spin configuration (state ¦alpha(0)>)
c     phs = staggered phase
c     ap1 = factor in acceptance probability for 0-->1 diagonal update
c     dp1 = factor in acceptance probability for 1-->0 diagonal update
c------------------------------------------------------------------------------

      INTEGER l
      INTEGER nh
      INTEGER str(ll)
      INTEGER bst(2,nb)
      INTEGER spn(nn)
      INTEGER phs(nn)
      REAL*8  ap1
      REAL*8  dp1
      COMMON/CBLOCK/ap1,dp1,l,nh,str,bst,spn,phs

c-----------------------------------------------------------------------------