The compound K(3)PSe(4)(.)2Se(6) was synthesized at 110 degreesC via solventothermal techniques from binary starting materials and Se in acetonitrile. The compound crystallizes in the space group Fd (3) over bar of the cubic system with eight formula units in a cell with a dimension of a = 16.415(2) Angstrom at T = 193 K. The structure contains an unusual intermixing of ionic and uncharged species. The selenophosphate tetrahedral trianions PSe43- are surrounded by potassium cations; other potassium cations in the structure are coordinated to 12 selenium atoms from four Se-6 rings in a tetrahedral arrangement. There are no short contacts between adjacent selenium rings. Heating the same reaction mixture to 160 degreesC results in the formation of only needles of trigonal selenium.