Periodic density-functional theory (DFT) calculations were performed using the Vienna Ab initio Simulation Package (VASP) code. Initial structures were obtained from the Materials Project Database or taken from previous work. The PBEsol generalised-gradient approximation (GGA) functional was used to describe electron exchange and correlation. A Hubbard U correction of U eff = 4 eV was applied to the Sn d electrons using the method of Dudarev et al. The valence Kohn-Sham or-Table List of chalcogenide phases examined in this work with the number of atoms in the primitive (conventional) unit cells and the technical parameters used in the calculations: plane-wave cutoffs and k k k-point sampling meshes used for optimising the unit cells, supercell expansions and reduced k k k-point sampling used to determine the second-and third-order force constants Φ Φ Φ /Φ Φ Φ (FCs), and q q q-point sampling used to determine the lattice thermal conductivities κ κ κ latt . All parameters are based on the conventional unit cells.