In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 71, No. 5 ( 2016-5-1), p. 585-592
Abstract:
The crystal structures of the trigermanides AE Ge 3 ( tI 32) ( AE = Ca, Sr, Ba; space group I 4/ mmm , for SrGe 3 : a = 7.7873(1), c = 12.0622(3) Å) comprise Ge 2 dumbbells forming layered Ge substructures which enclose embedded AE atoms. The chemical bonding analysis by application of the electron localizability approach reveals a substantial charge transfer from the AE atoms to the germanium substructure. The bonding within the dumbbells is of the covalent two-center type. A detailed analysis of SrGe 3 reveals that the interaction on the bond-opposite side of the Ge 2 groups is not lone pair-like – as it would be expected from the Zintl-like interpretation of the crystal structure with anionic Ge layers separated by alkaline-earth cations – but multi-center strongly polar between the Ge 2 dumbbells and the adjacent metal atoms. Similar atomic interactions are present in CaGe 3 and BaGe 3 . The variation of the alkaline-earth metal has a merely insignificant influence on the superconducting transition temperatures in the s , p -electron compounds AE Ge 3 .
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.1515/znb-2016-0047
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2016
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
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