The Ethanedioicacid, erbium(3+) salt, hydrate (3:2:10), with the CAS registry number 30618-31-6, is also known as Erbium oxalate, 99.9%. This chemical's molecular formula is C₆H₂₀Er₂O₂₂ and molecular weight is 778.7278. Its IUPAC name is called erbium(3+); oxalate; decahydrate. 

Physical properties of Ethanedioicacid, erbium(3+) salt, hydrate (3:2:10): (1)H-Bond Donor: 10; (2)H-Bond Acceptor: 22; (3)Rotatable Bond Count: 0; (4)Exact Mass: 777.90728; (5)MonoIsotopic Mass: 775.905202; (6)Topological Polar Surface Area: 251; (7)Heavy Atom Count: 30; (8)Formal Charge: 0; (9)Complexity: 60.5; (10)Covalently-Bonded Unit Count: 15.

When you are using this chemical, please be cautious about it as the following:
This chemical is harmful by inhalation, in contact with skin and if swallowed. It is irritating to eyes, respiratory system and skin. In case of contact with eyes, you should rinse immediately with plenty of water and seek medical advice. Whenever you will contact it, please wear suitable protective clothing, gloves and eye/face protection.

You can still convert the following datas into molecular structure:
(1)Canonical SMILES: C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].O.O.O.O.O.O.O.O.O.O.[Er+3].[Er+3]
(2)InChI: InChI=1S/3C2H2O4.2Er.10H2O/c3*3-1(4)2(5)6;;;;;;;;;;;;/h3*(H,3,4)(H,5,6);;;10*1H2/q;;;2*+3;;;;;;;;;;/p-6
(3)InChIKey: OVECSXKDHFDFMD-UHFFFAOYSA-H