title: In search of the elusive amalgam SrHg8: a mercury-rich intermetallic compound with augmented pentagonal prisms.
abstract: In confirmation of its predicted existence in the Sr-Hg phase diagram, the mercury-rich intermetallic compound SrHg(8) has been prepared by reaction of the elements at 200 degrees C. Single-crystal X-ray diffraction analysis revealed that it adopts a new structure type (Pearson symbol oP72, space group Pnma, a = 13.328(1) A, b = 4.9128(5) A, c = 26.446(3) A). The Sr atoms are centred within two types of 18-vertex Hg polyhedra formed by augmenting pentagonal prisms with octagonal waists. The condensation of these Sr@Hg(18) clusters is associated with the formation of a complex anionic Hg-Hg bonding network, as supported by electronic structure calculations which reveal strong mixing of Hg 6s and 6p states in highly delocalized bands superimposed with a narrower 5d band below the Fermi level.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
authors.forename: Andriy V
authors.initials: AV
authors.lastname: Tkachuk
authors.forename: Arthur
authors.initials: A
authors.lastname: Mar
mesh_terms: D018360:Crystallography, X-Ray; D008628:Mercury / Q000737:chemistry*; D008958:Models, Molecular; D013324:Strontium / Q000737:chemistry*
chemical_list: D008628:Mercury; D013324:Strontium