Calcium filled skutterudites CaxCo4Sb12: effect of the computational approach on the ab-initio modeled electronic transport properties

Fully filled CaCo4Sb12 system is selected as a test case for probing how the ab-initio modeled electronic transport properties are affected by the computational level. The periodic wave functions for the various adopted models are calculated by means of the Density Functional Theory (DFT) approach using local gaussian atomic basis sets, while the relevant electronic transport properties are obtained from the band structure using the semi-classical Boltzmann transport theory. This two-step computational procedure is tested against the atomic basis set quality, the band structure adopted in the frozen band approach and the DFT functional form. From this extensive test, a reliable computational level for CaCo4Sb12 is identified and the experimental findings on the Ca-filled systems are discussed in the light of, and compared with, the results from computations.