ic051981p_si_001.pdf (215.89 kB)
Electronic Structures of KNa3In9 and Na2In, Two Metallic Phases with Classical Closed-Shell Electronic Configurations
journal contribution
posted on 2006-04-03, 00:00 authored by Bin Li, John D. CorbettThe cluster compounds KNa3In9 [K2Na6(In12)(In)6] and Na2In [(Na)8(In4)], which contain In12 icosahedra interbridged
by 4-bonded In atoms and isolated In4 tetrahedra, respectively, both have classical closed-shell electronic
configurations but show metallic transport properties. These contrasts have been studied by means of first-principles
density functional methods (LMTO-ASA). Several bands cross the Fermi level in both compounds, consistent with
their metallic properties. In KNa3In9, the metal atom framework alone is sufficient to generate a metallic characteristic.
The alkali-metal s and indium p orbitals mix considerably in both phases, providing for substantial covalent contributions
to their stabilities as well as bands crossing Ef. The participation of Na atoms in the 3D bonding networks is more
striking in cation-richer Na2In than in KNa3In9.