H©Cu4I4–: A Planar Tetracoordinate Hydrogen Superhalogen Anion Stabilized by Covalent Multicenter Bonding | Inorganic Chemistry pubs.acs.org/doi/10.1021/... Guo and co-workers @InorgChem #copper #hydrogen #superhalogen #H_Cu4I4minus #ptH #GM #CK #covalent