We consider DIB-S n -DIB as target molecules in vacuum as a local structure of poly(sulfur-n-1,3-diisopropenylbenzene), where n = 4 and 8, representing copolymers consisting of short and long sulfur chains, respectively. In S/DIB copolymers, a sulfur chain connects to two DIB molecules. The terminal sulfur atoms forming C-S bonds are usually referred to as organic sulfur atoms. The C-S bonds remain stable during reactions with lithium, resulting in lithium-saturated chains where the number of lithium atoms reacting with the sulfur chain is twice the number of sulfur atoms minus two. Therefore, consecutive lithiation reactions of S/DIB copolymers are described by