def spaced_string_iijjkk1_for_box_kji0(box_kji0, colon_separator = ' '):
    """Returns a string representing the box space in simulator input format, eg. '1 5  3 20  100 103'.

    input arguments (unmodified):
       box_kji0: numpy int array of shape (2, 3)
          lower & upper indices in 3 dimensions defining a logical cuboid subset of a 3D cartesian grid
          with python kji ordering and zero start for indices
       colon_separator: string (typically ':' or ' ')
          the character(s) included in the return string between lower and upper bounds in each direction

    returns: string
       ascii representation of box in Fortran/simulator ijk protocol starting 1, suitable for use in include files
    """

    return str(box_kji0[0, 2] + 1) + colon_separator + str(box_kji0[1, 2] + 1) + '  ' +  \
           str(box_kji0[0, 1] + 1) + colon_separator + str(box_kji0[1, 1] + 1) + '  ' +  \
           str(box_kji0[0, 0] + 1) + colon_separator + str(box_kji0[1, 0] + 1)