Bonding in the BaPdSn₃Structure

The body-centered BaPdSn₃ structure contains Sn atoms in tetrahedral and square-pyramidal five-coordinate sites, and Pd in square-pyramidal environments. The PdSn₃^2- three-dimensional lattice can be formally decomposed into first two-dimensional layers. then into a square Sn lattice with capping Sn and Pd atoms. This geometrical decomposition also serves as a construction principle for building up the electronic structure of this material. Many similarities to BaAl₄ 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.