Finding new thermoelectric compounds using crystallographic data: Atomic displacement parameters

A new structure-property relationship is discussed which links atomic displacement parameters (ADPs) and the lattice thermal conductivity of clathrate-like compounds. For many clathrate-like compounds, in which one of the atom types is weakly bound and `rattles' within its atomic cage, room temperature ADP information can be used to estimate the room temperature lattice thermal conductivity, the vibration frequency of the `rattler', and the temperature dependence of the heat capacity. Neutron data and X-ray crystallography data, reported in the literature, are used to apply this analysis to several promising classes of thermoelectric materials.