Noble gas–sulfur anions: A theoretical investigation of FNgS− (Ng=He, Ar, Kr, Xe)

MP2, coupled-cluster, and multireference–CI calculations were performed to investigate the structure, stability, and properties of the noble gas anions FNgS − (Ng = He, Ar, Kr, Xe). Similar to the recently investigated FNgO − and FNgBN − , these species reside into deep wells on the singlet surface, protected by sizable barriers with respect to FS − + Ng and F − + Ng + S( 3 P). Their stability arises from the strong F − -stabilization of the elusive NgS. The lightest FHeS − and FArS − are also first predicted examples of helium–sulfur and argon–sulfur molecular species.