Empirical Formula of Nickel ammonium sulfate (2:2:3) (CAS NO.25749-08-0): H₁₂N₂Ni₂O₁₂S₃
Molecular Weight: 445.6833 
Boiling Point: 330 °C at 760 mmHg
Vapour Pressure: 3.35E-05 mmHg at 25 °C
Structure of Nickel ammonium sulfate (2:2:3) (CAS NO.25749-08-0):
                 
IUPAC Name: Azane ; Nickel ; Sulfuric acid
Canonical SMILES: N.N.OS(=O)(=O)O.OS(=O)(=O)O.OS(=O)(=O)O.[Ni].[Ni]
InChI: InChI=1S/2H3N.2Ni.3H2O4S/c;;;;3*1-5(2,3)4/h2*1H3;;;3*(H2,1,2,3,4)
InChIKey: ZTIBLSFDOTXLGD-UHFFFAOYSA-N

NTP 10th Report on Carcinogens. IARC Cancer Review: Animal Limited Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 49 ,1990,p. 257.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) .

Confirmed human carcinogen. When heated to decomposition Nickel ammonium sulfate (2:2:3) (CAS NO.25749-08-0) emits toxic vapors of SO_x, NO_x, and Ni.

ACGIH TLV: TWA 0.1 mg(Ni)/m³; Not Classifiable as a Carcinogen

 Nickel ammonium sulfate (2:2:3) , its cas register number is 25749-08-0. It also can be called Sulfuric acid, ammonium nickel(2+) salt (3:2:2) ; and Nickel ammonium sulfate .