c***********************************************************************
c     common block containing the constants controlling different 
c     algorithms 
c*** 
      DOUBLE PRECISION angledif, omega, mingrad, epsc, epsurr, norm_old,
     % mineps  
      INTEGER cycles, ncycle, ncycle_old, npre, npost, ntop,
     % relax_times, relax_times_old, printres
      COMMON /DIFF/ angledif, mingrad, epsc, epsurr
      COMMON /CYCLING/ omega, cycles, npre, npost, ntop, relax_times,
     % relax_times_old, ncycle, ncycle_old, norm_old, mineps, printres