17^th Group

• Default: HF, HCl, HBr, HI, HAt

• Molecules:

  • Neutral atoms: 1 bond is allowed.

     *Exceptions:*
    

    • 3 valence:

      • Two of the ligands should be F, Cl or oxygen; and one more atom from the 14^th, 15^th, 16^th columns.
      • Double bonded oxygen and one any other atom from 14^th, 15^th, 16^th columns are also accepted.

    • 5 valence:

      • Four of the ligands should be F, Cl or oxygen; and one more atom from the 14^th, 15^th, 16^th columns. Double bonded oxygens are accepted.

    • 7 valence:

      • IF₇ is accepted.

    • Halogen oxoacids:

      • HXO_y, where X = Cl, Br, I or At; and y = 2, 3 or 4.

• Ions:

  • F^-, Cl^-, Br^-, I^-, At^- are accepted.
  • 1+ charged ions: 2 filled valences are necessary (bonds or radicals). If absent, implicit Hydrogen atoms added.

• Radicals:

  • 1 Radical with 0 bond around the halogen atom is accepted.