PARAMETER (NROW =1024)      ! maximum number of particles in 1D
      PARAMETER (NGRID =256)      ! zero-level mesh in 1D
                                  ! must be equal to ng in ART
      PARAMETER (Nmaxpart = 256**3)  ! max number of particles for this run
                                  ! Nmaxpart must be less than NROW**3
      PARAMETER (nbyteword = 4)   ! defines length of direct-access:1or4
      PARAMETER (Lblock=8)