Previous theoretical studies have predicted p-type ZT of 0.6 for π SnS at 800 K and ZT between 0.74 and 1 between 300-900 K. At the same T = 800 K and n = 10 20 cm -3 employed in Ref. , we predict larger p-type ZT = 1.21 and 1.25 for π SnS and SnSe. This study also predicted higher S 2 σ with p-type doping, in contrast to our results, which is likely due to the neglect of POP scattering in calculating the σ as noted above. The calculated ZT in Ref. are obtained by neglecting the κ latt entirely, while Ref. estimates the κ latt with the Slack model and uses a constant electron relaxation time to calculate the σ and κ el , all of which are likely to be poor approximations. However, since neither study specifies the carrier concentration(s) at which the ZT were calculated, it is impossible to compare to our calculations.