Calculated electron densities andsp3-bonding character for binary and ternary Zintl phases

Abstract

Self-consistent electronic structures and bond orbitals constructed from ${\mathrm{sp}}^3$-hybridized atom-centered orthogonal linear muffin-tin orbitals (LMTO’s) are used to study the bonding properties of Zintl phases. Calculation of the relative bonding-antibonding character allows a study of trends in the bonding. The examination includes binary (LiM with M=B–Tl, NaIn, and NaTl) and ternary (LiAlSi) Zintl phases. In this way it is possible to obtain quantitative values for the ‘‘degree of ${\mathrm{sp}}^3$ bonding’’ in these compounds. The trends follow those found in B2-B32 structural energy differences. Furthermore, by transforming the LMTO’s to the localized basis we calculate the full nonspherical charge distributions.