[{"from": "human", "value": "Generate a molecule based on this description. The molecule is a sulfide of tin that occurs naturally as the rare mineral berndtite. It is used in decorative coating, where it is known as mosaic gold. Tin is a chemical element with the symbol Sn and atomic number 50. It is a natural component of the earth's crust and is obtained chiefly from the mineral cassiterite, where it occurs as tin dioxide. (L307, L309, L323)"}, {"from": "gpt", "value": "[S-2].[S-2].[Sn]"}]