The name/synonym for ligand MN (curated from ChEBI, PubChem, and PDB databases):

1MANGANESE(2+)
2MANGANESE(II)
3MN(2+)
4MANGANESE, ION (MN2+)
5MANGANOUS ION
6MANGANESE (II) ION
7MANGANESE(2+) ION
8MANGANESE(II) CATION
9MN++