X-ray Crystal Structures of α-KrF2, [KrF][MF6] (M = As, Sb, Bi), [Kr2F3][SbF6]·KrF2, [Kr2F3]2[SbF6]2·KrF2, and [Kr2F3][AsF6]·[KrF][AsF6]; Synthesis and Characterization of [Kr2F3][PF6]·nKrF2; and Theoretical Studies of KrF2, KrF+, Kr2F3+, and the [KrF ...