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

1COPPER(2+)
2COPPER, ION (CU2+)
3CU(2+)
4COPPER(II) CATION
5CUPRIC ION
6CU2+
7COPPER(2+) ION
8CU(II)
9COPPER (II) ION
10COPPER