title: More Than 50 Years after Its Discovery in SiO2Octahedral Coordination Has Also Been Established in SiS2at High Pressure.
abstract: SiO2exhibits a high-pressure-high-temperature polymorphism, leading to an increase in silicon coordination number and density. However, for the related compound SiS2such pressure-induced behavior has not been observed with tetrahedral coordination yet. All four crystal structures of SiS2known so far contain silicon with tetrahedral coordination. In the orthorhombic, ambient-pressure phase these tetrahedra share edges and achieve only low space filling and density. Up to 4 GPa and 1473 K, three phases can be quenched as metastable phases from high-pressure high-temperature to ambient conditions. Space occupancy and density are increased first by edge and corner sharing and then by corner sharing alone. The structural situation of SiS2up to the current study resembles that of SiO2in 1960: Then, in its polymorphs only Si-O4tetrahedra were known. But in 1961, a polymorph with rutile structure was discovered: octahedral Si-O6coordination was established. Now, 50 years later, we report here on the transition from 4-fold to 6-fold coordination in SiS2, the sulfur analogue of silica.
authors.affiliation: Department of Chemistry, Ludwig-Maximilian University of Munich , Butenandtstraße 5-13, D-81377 Munich, Germany.
authors.forename: Jürgen
authors.identifier: http://orcid.org/0000-0001-9434-3191
authors.initials: J
authors.lastname: Evers
authors.affiliation: Department of Chemistry, Ludwig-Maximilian University of Munich , Butenandtstraße 5-13, D-81377 Munich, Germany.
authors.forename: Leonhard
authors.initials: L
authors.lastname: Möckl
authors.affiliation: Department of Chemistry, Ludwig-Maximilian University of Munich , Butenandtstraße 5-13, D-81377 Munich, Germany.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Oehlinger
authors.affiliation: Karlsruher Institut für Technologie (KIT), Institut für Anorganische Chemie , Engesserstraße 15, Gebäude 30.45, D-76131 Karlsruhe, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Köppe
authors.affiliation: Karlsruher Institut für Technologie (KIT), Institut für Anorganische Chemie , Engesserstraße 15, Gebäude 30.45, D-76131 Karlsruhe, Germany.
authors.forename: Hansgeorg
authors.initials: H
authors.lastname: Schnöckel
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe , Nöthnitzer Straße 40, D-01187 Dresden, Germany.|Institute of Solid State Physics, Russian Academy of Sciences , Academician Ossipyan Street 2, Chernogolovka, Moscow District, 142432, Russia.
authors.forename: Oleg
authors.initials: O
authors.lastname: Barkalov
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe , Nöthnitzer Straße 40, D-01187 Dresden, Germany.
authors.forename: Sergey
authors.initials: S
authors.lastname: Medvedev
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe , Nöthnitzer Straße 40, D-01187 Dresden, Germany.|Shubnikov Institute of Crystallography of Federal Scientific Research Center "Crystallography and Photonics" of Russian Academy of Sciences , Leninskii Prospekt 59, Moscow, 119333, Russia.
authors.forename: Pavel
authors.initials: P
authors.lastname: Naumov