15th Group

Nitrogen (N)

• Default: NH₃

• Molecules:

  • Neutral atoms

    • Implicit hydrogens are added to have 3 bonds (if nitrogen has at least 1 bond).

      More than 3 bonds are forbidden.

      If nitrogen has 4 ligands, charge is not set, hence not accepted

      Pentavalent N is accepted in traditional form by default, but keep in mind that these forms are not correct. Use the "ylide" from of the N atom which satisfies the correct valence electron count:

      traditional form	"ylide" form

    • It's possible to accept only the "ylide" form using the MoleculeGraph.setValenceCheckOptions() function.

  • Charged atoms in a molecule:

    • Positive charge:

      • 1+: 4 bonds needed (incluing implicit hydrogens)

      • 2+: 3 bonds needed (incluing implicit hydrogens)

      • 3+: 2 bonds needed (incluing implicit hydrogens)

      • 4+: 1 bonds needed (incluing implicit hydrogens)

      • 5+: 0 bonds needed (incluing implicit hydrogens)

      • 6+ or more: not allowed

    • Negative charge: Every added negative charge decreases by one the number of possible bonds. Maximum charge accepted is -3.

  • Radical: Every added radical on these atoms decreases by one the number of bonds. Maximum three added radical is allowed.

  • Aromatic compounds: Nitrogen may form aromatic bonds as well.

Phosphorus (P), Arsenic (As), Antimony (Sb), Bismuth (Bi)

• Default: PH₃, AsH₃, SbH₃, Bi

• Molecules:

  • Neutral atoms:

    • 1 bond: 2 implicit Hydrogens are added.

    • 2 bond: 1 implicit Hydrogen is added.

    • 3 bond: 0 implicit Hydrogen is added.

    • 4 bond: 1 implicit Hydrogen is added.

    • 5 bond: 0 implicit Hydrogen is added.

    • More than 5 bonds are forbidden

  • Charged atoms in a molecule:

    • Positive charge:

      • 1+: 4 bonds are necessary (including implicit Hydrogens).

      • 2+: 3 bond is necessary (including implicit Hydrogens).

      • 3+: 2 bond is allowed.

      • 4+: 1 bond is necessary (including implicit Hydrogens).

      • 5+: 0 bond is allowed.

      • 6+ or more: not allowed

    • Negative charge: Every added negative charge decreases by one the number of possible bonds. Maximum charge accepted is -3.

  • Radical: Every added radical on these atoms decreases by one the number of bonds. Maximum three added radicals are allowed.

  • Aromatic compounds: Phosphorus may form aromatic bonds as well.