Nitrosodisulfide [S₂NO]^- (perthionitrite) is a true intermediate during the "cross-talk" of nitrosyl and sulfide

Nitrosodisulfide S₂NO^- is a controversial intermediate in the reactions of S-nitrosothiols with HS^- that produce NO and HNO. QM-MM molecular dynamics simulations combined with TD-DFT analysis contribute to a clear identification of S₂NO^- in water, acetone and acetonitrile, accounting for the UV-Vis signatures and broadening the mechanistic picture of N/S signaling in biochemistry.