What is "phosphorus sulfide"

Phosphorus sulfides comprise a family of inorganic compounds containing only phosphorus and sulfur. These compounds have the formula PS with x ≤ 10. Two are of commercial significance, phosphorus pentasulfide (PS), which is made on a kiloton scale for the production of other organosulfur compounds, and phosphorus sesquisulfide (PS), used in the production of "strike anywhere matches".

There are several other phosphorus sulfides in addition to PS and PS. Six of these phosphorus sulfides exist as isomers: PS, PS, PS, PS, PS, and PS. These isomers are distinguished by Greek letter prefixes. The prefix is based on the order of the discovery of the isomers, not their structure. All known molecular phosphorus sulfides contain a tetrahedral array of four phosphorus atoms. PS is also known but is unstable above −30 °C.