title: Unexpected Ge-Ge Contacts in the Two-Dimensional Ge4Se3Te Phase and Analysis of Their Chemical Cause with the Density of Energy (DOE) Function.
abstract: A hexagonal phase in the ternary Ge-Se-Te system with an approximate composition of GeSe0.75Te0.25has been known since the 1960s but its structure has remained unknown. We have succeeded in growing single crystals by chemical transport as a prerequisite to solve and refine the Ge4Se3Te structure. It consists of layers that are held together by van der Waals type weak chalcogenide-chalcogenide interactions but also display unexpected Ge-Ge contacts, as confirmed by electron microscopy analysis. The nature of the electronic structure of Ge4Se3Te was characterized by chemical bonding analysis, in particular by the newly introduced density of energy (DOE) function. The Ge-Ge bonding interactions serve to hold electrons that would otherwise go into antibonding Ge-Te contacts.
authors.affiliation: Institute of Inorganic Chemistry, Chair of Solid-State and Quantum Chemistry, RWTH Aachen University, Landoltweg 1, 52056, Aachen, Germany.
authors.forename: Michael
authors.identifier: 0000-0002-8295-614X
authors.initials: M
authors.lastname: Küpers
authors.affiliation: Institute of Inorganic Chemistry, Chair of Solid-State and Quantum Chemistry, RWTH Aachen University, Landoltweg 1, 52056, Aachen, Germany.
authors.forename: Philipp M
authors.identifier: 0000-0002-7946-702X
authors.initials: PM
authors.lastname: Konze
authors.affiliation: Institute of Inorganic Chemistry, Chair of Solid-State and Quantum Chemistry, RWTH Aachen University, Landoltweg 1, 52056, Aachen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Maintz
authors.affiliation: Institute of Inorganic Chemistry, Chair of Solid-State and Quantum Chemistry, RWTH Aachen University, Landoltweg 1, 52056, Aachen, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Steinberg
authors.affiliation: I. Physikalisches Institut (IA), RWTH Aachen University, Germany.
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Mio
authors.affiliation: I. Physikalisches Institut (IA), RWTH Aachen University, Germany.
authors.forename: Oana
authors.initials: O
authors.lastname: Cojocaru-Mirédin
authors.affiliation: I. Physikalisches Institut (IA), RWTH Aachen University, Germany.
authors.forename: Min
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Gemeinschaftslabor für Elektronenmikroskopie, RWTH Aachen University, Germany.
authors.forename: Merlin
authors.initials: M
authors.lastname: Müller
authors.affiliation: Ernst-Ruska-Center, Forschungszentrum Jülich GmbH, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Luysberg
authors.affiliation: Gemeinschaftslabor für Elektronenmikroskopie, RWTH Aachen University, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Mayer
authors.affiliation: I. Physikalisches Institut (IA), RWTH Aachen University, Germany.
authors.forename: Matthias
authors.identifier: 0000-0003-1498-1025
authors.initials: M
authors.lastname: Wuttig
authors.affiliation: Institute of Inorganic Chemistry, Chair of Solid-State and Quantum Chemistry, RWTH Aachen University, Landoltweg 1, 52056, Aachen, Germany.|Jülich-Aachen Research Alliance (JARA-HPC), RWTH Aachen University, 52056, Aachen, Germany.
authors.forename: Richard
authors.identifier: 0000-0002-1925-9624
authors.initials: R
authors.lastname: Dronskowski
keywords: DOE; X-ray diffraction; ab initio calculations; chalcogenides; solid-state structures