Structure and chemical bonding of Ce2Ge2In and Ce2Pt2In

Ce2Ge2In was synthesized by are-melting the elements under argon. Its Mo2FeB2 type structure was refined on the basis of the single crystal data: P4/mbm, a = 756.3(1), c = 438.1(1) pm, omega R2 = 0.0456, 339 F-2 values and 12 variable parameters. The structure is an intergrowth of distorted AlB2 and CsCl related slabs of compositions CeGe2 and CeIn with a Ge-Ge distance of 253 pm within the AlB2 slabs. The COHP analysis confirms strong covalent Ge-Ge bonds, which determines the structure more than the corresponding Pt-Pt bonds in isostructural Ce2Pt2In. The weaker Pt-Pt bonding energy is compensated by stronger Ce-Pt interactions, which results in almost identical total ICOHP bonding energies for Ce2Pt2In and Ce2Ge2In. (c) 2005 Elsevier SAS. All rights reserved.