c
c  atomnames: change the atom names of a pdb file from
c             the tinker names to charmm/namd names
c
c  usage atomnames < test.pdb > newpdb.pdb
c
c  Leandro Martinez, Jan 2005
c  http://www.ime.unicamp.br/~martinez/packmol
c

      implicit double precision (a-h,o-z)

      character*80 record
      character*5 atom
      character*4 resid

      do while(.true.)
        read(*,10,end=20,err=20) record
        if(record(1:4).eq.'ATOM'.or.record(1:6).eq.'HETATM') then
          atom = '     '
          read(record(13:17),*) atom
          read(record(18:21),*) resid
          call change(atom,resid)
          leng = 0
          do i = 1, 5
            if(atom(i:i).gt.' ') leng = leng + 1
          end do
          record(13:17) = '     '
          if(leng.ge.4) record(13:17) = atom(1:5)
          if(leng.lt.4) record(14:17) = atom(1:4)
          leng = 0
          do i = 1, 4
            if(resid(i:i).gt.' ') leng = leng + 1
          end do  
          record(18:21) = '    '
          if(leng.lt.4) record(18:20) = resid(1:3)
          if(leng.ge.4) record(18:21) = resid(1:4)
        end if
        write(*,10) record
      end do
20    continue

10    format(a80)

      end

      subroutine change(atom,resid)
      character*5 atom, temp
      character*4 resid

      if(atom.eq.'H') atom = 'HN'
      if(atom.eq.'1H') atom = 'HT1'
      if(atom.eq.'2H') atom = 'HT2'
      if(atom.eq.'3H') atom = 'HT3'
      if(atom.eq.'1HB') atom = 'HB1'
      if(atom.eq.'2HB') atom = 'HB2'
      if(atom.eq.'3HB') atom = 'HB3'
      if(atom.eq.'1HG') atom = 'HG1'
      if(atom.eq.'2HG') atom = 'HG2'
      if(atom.eq.'1HE2') atom = 'HE21'
      if(atom.eq.'2HE2') atom = 'HE22'
      if(atom.eq.'1HD') atom = 'HD1'
      if(atom.eq.'2HD') atom = 'HD2'
      if(atom.eq.'1HH1') atom = 'HH11'
      if(atom.eq.'2HH2') atom = 'HH22'
      if(atom.eq.'1HH2') atom = 'HH21'
      if(atom.eq.'2HH1') atom = 'HH12'
      if(atom.eq.'1HG2') atom = 'HG21'
      if(atom.eq.'2HG2') atom = 'HG22'
      if(atom.eq.'3HG2') atom = 'HG23'
      if(atom.eq.'3HG1') atom = 'HG13'
      if(atom.eq.'1HD1') atom = 'HD11'
      if(atom.eq.'2HD1') atom = 'HD12'
      if(atom.eq.'3HD1') atom = 'HD13'
      if(atom.eq.'1HD2') atom = 'HD21'
      if(atom.eq.'2HD2') atom = 'HD22'
      if(atom.eq.'3HD2') atom = 'HD23'
      if(atom.eq.'1HE2') atom = 'HE21'
      if(atom.eq.'HE22') atom = 'HE22'
      if(atom.eq.'1HA') atom = 'HA1'
      if(atom.eq.'2HA') atom = 'HA2'
      if(atom.eq.'1HE') atom = 'HE1'
      if(atom.eq.'2HE') atom = 'HE2'
      if(atom.eq.'3HE') atom = 'HE3'
      if(atom.eq.'1HG1') atom = 'HG11'
      if(atom.eq.'2HG1') atom = 'HG12'
      if(atom.eq.'1HD1') atom = 'HD11'
      if(atom.eq.'2HD1') atom = 'HD21'
      if(atom.eq.'3HD1') atom = 'HD31'
      if(atom.eq.'1HZ') atom = 'HZ1'
      if(atom.eq.'2HZ') atom = 'HZ2'
      if(atom.eq.'3HZ') atom = 'HZ3'
      if(atom.eq.'HG'.and.resid.eq.'SER') atom = 'HG1'
      if(atom.eq.'HG'.and.resid.eq.'CYS') atom = 'HG1'
      if(resid.eq.'ILE'.and.atom.eq.'CD1') atom = 'CD'
      if(atom.eq.'OXT') atom = 'OT1'

      end