Li20Mg6Cu13Al42: a new ordered quaternary superstructure to the icosahedral T‐Mg32(Zn, Al)49 phase with fullerene‐like Al60 cluster. Issue 2 (9th April 2019)

• Record Type: Journal Article
• Authors: Pavlyuk, Nazar; Dmytriv, Grygoriy; Pavlyuk, Volodymyr; Ehrenberg, Helmut
• Is Part Of: Acta crystallographica. Volume 75:Issue 2(2019:Apr.)
• Page Start: 168
• Page End: 174
• Publication Date: 2019-04-09
• Subjects: intermetallics -- icosahedral clusters -- structural relations -- electronic structure calculations -- chemical bonding -- quaternary systems -- single‐crystal methods -- triacontahedrons -- core–shell packing
• DOI: 10.1107/S2052520619000349
• Languages: English
• ISSNs: 2052-5206

Abstract

Abstract : The new quaternary aluminide Li20 Mg6 Cu13 Al42 was studied by the single‐crystal method: cI 162, , a = 13.8451 (2), R [ F 2 > 2σ( F 2 )] = 0.023. The Li20 Mg6 Cu13 Al42 structure can also be described as three‐shell icosahedral clusters of [CuAl12@Li20Cu12@Al60] which can be enclosed inside a truncated octahedron of magnesium atoms in which all hexagonal faces are centered by lithium atoms. The electronic structure calculations confirm the concept of core–shell packing of clusters. Abstract : The new quaternary aluminide Li20 Mg6 Cu13 Al42 was synthesized from the elements in a sealed tantalum crucible. The crystal structure was studied by single crystal and confirmed by X‐ray powder diffraction. Li20 Mg6 Cu13 Al42 { cI 162, , a = 13.8451 (2), R [ F 2 > 2σ( F 2 )] = 0.023} crystallizes as an ordered version of Mg32 (Al, Zn)49 and Li—Cu— X ( X = Al, Ga, Si) periodic crystals containing icosahedral clusters. The Li20 Mg6 Cu13 Al42 structure can also be described as three‐shell icosahedral clusters of [CuAl12 @Li20 Cu12 @Al60 ], enclosed inside a distorted triacontahedron. The electronic structure calculations were performed by means of the TB‐LMTO‐ASA program and confirm the core–shell packing of these clusters. The isostructural compound of Li20 Mg6 Cu13 Ga42 was found in a Li–Mg–Cu–Ga quaternary system.