Bonding in the BaPdSn3 Structure

The body-centered BaPdSn3 structure contains Sn atoms in tetrahedral and square-pyramidal five-coordinate sites, and Pd in square-pyramidal environments. The PdSn32three-dimensional lattice can be formally decom posed into first two-dimensional layers, then into a square Sn lattice with capping Sn and Pd atoms. This geometrical decom position also serves as a construction principle for building up the electronic structure of this material. Many similarities to B aA l4 emerge. There is electron deficient multicenter bonding in the layer, normal two-center bonding Sn—Pd between layers. Pd 4d orbitals do not contribute significantly to the bonding.