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. 
 
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-     Charged atoms: -     Positive charge: Every added charge decreases by one the number of possible bonds. Maximum charge accepted is +3. 
-     Negative charge: BH4-, BH32- BH23- BH4- and B5- are accepted. 
 
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-     Radicals: Every added radical on these atoms decreases by one the number of necessary bonds. 
-     Aromatic compounds: Boron may form aromatic bonds as well. 
 
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Aluminium (Al), Gallium (Ga), Indium (In), Thallium (Tl)
-     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. 
 
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-     Radicals: Every added radical on these atoms decreases by one the number of necessary bonds. 
 
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-     Ions: -     Al+, Ga+, In+, Rb+, Al3+, Ga3+, In3+, Rb3+ are accepted. 
 
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-     Radical: ·Me2+ and ·?Me· are allowed.