6-Amino-1,3-dimethyl-5-[(<i>E</i>)-2-(methylsulfanyl)benzylideneamino]pyrimidine-2,4(1<i>H</i>,3<i>H</i>)-dione–1,3,7,9-tetramethylpyrimido[5,4-<i>g</i>]pteridine-2,4,6,8-tetrone (1/1)
Acta crystallographica. Section E