Due to the recent success of Mg 3 Bi 2 -based materials for low-and room-temperature TE applications, we compare the estimated maximum zT of the 44 Zintl phases to that of Mg 3 Bi 2 . We downselect 20 phases using the criteria explained in Section 3.1 and perform higher accuracy electronic structure calculation with the hybrid HSE06 functional, with the exchange mixing parameter set to 25%. Spin-orbit coupling is included in all calculations. The structures are relaxed with HSE06 functional prior to calculating the electronic band structure. We use the HSE06 electronic structure to calculate E g and m ⇤ b , which are then used as inputs to estimate the maximum zT at 300 K.