The effect of strain on the structure of SnS

Tin sulfides are important for semiconductor technologies with potential applications in optoelectronics and solar energy conversion. Bulk SnS has orthorhombic structure with the Pnma symmetry (space group No. 62), with a phase transition to a structure with the Cmcm symmetry (space group No. 63) at 875 K. It is also known that the rocksalt structure with the Fm-3m symmetry (space group No. 225) has been observed by epitaxial growth on rocksalt thin films. Here we present a first principles study of the high symmetry rocksalt structure and its relation to the lower symmetry structures. Furthermore, we investigate the changes to the structure under different epitaxial strain conditions.