RESIDUE   KCS      6
CONECT      SAA    2 CAB  HSAA
CONECT      CAB    3 SAA  SAC  SAD 
CONECT      SAC    1 CAB 
CONECT      SAD    2 CAB  HSAD
CONECT      HSAA   1 SAA 
CONECT      HSAD   1 SAD 
END   
HET    KCS              6
HETSYN     KCS Trithiocarbonic acid
HETNAM     KCS carbonotrithioic acid
FORMUL      KCS    C1 H2 S3