catena-Poly[[tetra­kis(hexa­methyl­phospho­ramide-κO)bis­(nitrato-κ(2) O,O′)lanthanum(III)] [silver(I)-di-μ(2)-sulfido-tungstate(VI)-di-μ(2)-sulfido]]

Hexamethyl­phospho­ramide (hmp), tetra­thio­tungstate(VI), silver sulfide and lanthanum(III) nitrate are self-assembled to form discrete cations one-dimensional poylmeric anionic chains [AgWS(4)](n)(n) (−) in the title compound, {[La(NO(3))(2)(C(6)H(18)N(3)OP)(4)][AgWS(4)]}(n). The central La atom in the cation is coordinated by eight O atoms from two nitrate and four hmp ligands. Together with the two nitrate ligands, the cation is monovalent, which leads to the anionic chain having a monovalent repeat unit. The polymeric anionic chain with W⋯Ag⋯W and Ag⋯W⋯Ag angles of 165.94 (3) and 155.894 (14)° presents a distorted linear configuration. Five N atoms, 18 C atoms and their attached H atoms are disordered equally over two positions.