13th Group

Boron

Default: BH₃
Molecules:
- Neutral atoms:
  - Implicit Hydrogens are added to have 3 bonds.
  - 4 bonds are accepted with 1 negative charge on the boron atom.
  - 5 or more bonds are forbidden.
- Charged atoms:
  - Positive charge: Every added charge decreases by one the number of possible bonds. Maximum charge accepted is +3.
  - Negative charge: BH₄^-, BH₃^2- BH₂^3- BH^4- and B^5- are accepted.
- Radicals: Every added radical on these atoms decreases by one the number of necessary bonds.
- Aromatic compounds: Boron may form aromatic bonds as well.

Default: Al, Ga, In, Tl respectively.
Molecules:
- Neutral Atoms: 3 bonds around these atoms are accepted.
- Charged atoms:
  - Positive charge: Every added charge decreases by one the number of possible bonds. Maximum charge accepted is +3.
  - Negative charge: 4- charge with 4 ligands is accepted.
- Radicals: Every added radical on these atoms decreases by one the number of necessary bonds.
Ions:
- Al⁺, Ga⁺, In⁺, Rb⁺, Al³⁺, Ga³⁺, In³⁺, Rb³⁺ are accepted.
Radical: · Me²⁺ and · ? Me · are allowed.