Document Type

Article

Publication Version

Published Version

Publication Date

2004

Journal or Book Title

Journal of the American Chemical Society

Volume

126

Issue

16

First Page

5277

Last Page

5281

DOI

10.1021/ja030216b

Abstract

Theoretical reasons for metallic behavior among diverse Zintl phases have generally not been pursued at an advanced level. Here, the electronic structure of Ca5Ge3 (Cr5B3 type), which can be formulated (Ca+2)5(Ge2-6)Ge-4 in oxidation states, has been explored comparatively by means of semiempirical and first-principles density functional methods. The FP-APW calculations show that alkaline-earth-metal and germanium orbitals, particularly the d orbitals on the cations and the p-π* orbitals of the halogen-like dimeric Ge2-6, mix considerably to form a conduction band. This covalency perfectly explains the unusual metallic properties of the nominally electron-precise Zintl phase Ca5Ge3 and its numerous relatives. Similar calculational results are obtained for Sr5Ge3, Ba5Ge3, and Ca5Sn3. Cation d orbitals appear to be a common theme among Zintl phases that are also metallic.

Comments

Reprinted with permission from J. Am. Chem. Soc., 2004, 126 (16), pp 5277–5281. Copyright (2004) American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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