anchor.diff:         program pair_correlation
          implicit none
          integer i,l
  -       double precision lat(3,3),latv(3)
  +       double precision lat(3,3),latv(3),lat1(3,3)
          double precision rmax
          integer i1,j1,nb
          character*5 tvr
  
positive.code:        nf = 0
         do
           if(aformat.eq."trj") then
             call trj_read(fn_in,n,c,lat,ok)
           else if(aformat.eq."xyz")  then
             call xyz_read(n,c,atag,fn_in)
             ok=n.ne.0
           end if
           if(.not.ok) exit
           oc1=.false.
  
negative.code:        end if
  c      output file
         file_out = infile(nfil)
         message = "opening output file "//file_out
         open(fn_out,file=file_out,
       $            form='formatted',status='unknown',err=911)
  
         if(overb) then
           write(*,*) "lattice vectors"
  