ICT2014 Abstracts

Boltzmann Transport Theory based software is routinely used to aid in the design of thermoelectric materials. The approach has limitations, however, and ab-initio methods are necessary to overcome those limits. In this work, we outline all the steps necessary to perform an ab-initio calculation of electrical conductivity. We publish an open-source code based on the Kubo-Greenwood (KG) approach and Density Functional Theory (DFT), as implemented in Quantum Espresso. The application of KG requires careful setup of the system under study. The wrong preparations will lead to incorrect results. We detail the proper set up of an ensemble calculation of the temperature dependent conductivity using the example of single crystalline aluminum. The effect of cell size and periodic boundary conditions on the outcome are described. We contrast calculated results with experimental values and previous work. The computational requirements for electrical conductivity for different complexity classes of materials is also analyzed. The KG equation also allows for calculation of the Seebeck coefficient and electronic thermal conductivity and ongoing research to implement this approach is described.