  The transport properties of the perovskites KTaO$_3$ are calculated using
first-principles methods. Our study is based on Boltzmann transport theory and
the relaxation time approximation, where the scattering rate is calculated
using an analytical model describing the interactions of electrons and
longitudinal optical phonons. We compute the room-temperature electron mobility
and Seebeck coefficients of KTaO$_3$, and SrTiO$_3$ for comparison, for a range
of electron concentrations. The comparison between the two materials provides
insight into the mechanisms that determine room-temperature electron mobility,
such as the effect of band-width and spin-orbit splitting. The results,
combined with the efficiency of the computational scheme developed in this
study, provide a path to investigate and discover materials with targeted
transport properties.
