anchor.diff:         atom2_id = 0
          atom1_tag = " "
          atom2_tag = " "
  -       file_in = " "
  -       file_out = " "
          rmax = -1
          nb = -1
   c
   c      ------------------------
  -c      allocate input file array
  +c      allocate io file array
   c      ------------------------
          nc = my_command_argument_count()
  -       write(*,*) "nc=",nc
          call get_carg_nfiles(nc)
  -       write(*,*) "number of files",nc
          allocate(infile(nc))
  +       infile = " "
   c      --------------------------------------------      
   c      beging parsing command line arguments if any
   c      --------------------------------------------      
  
positive.code:        character*(180) buffer
         character*(180) message
         integer istatus
         logical overb,ohelp,odistinct
         character*255 file_lattice,file_in,file_out
         character*16 atom1_tag
         character*16 atom2_tag
  
negative.code:        fn_out = 11
         nfrm = 0
         aformat = " "
         overb = .false.
         file_lattice = " "
         latv = -1.0
         lat = 0.0
  