X-ray crystallography confirms the presence of C≡C subunits attached to lithium, resulting in a polymeric structure.

The other lithium-rich compounds are produced by reacting lithium vapor with chlorinated hydrocarbons, e.g. CCl4.

[citation needed] Other method for production of Li2C2 is heating of metallic lithium in atmosphere of ethylene.

[8] The outcome is the same: Li2C2 is produced, which can then be used to create species easy to use in mass spectroscopy, like acetylene and benzene.

[9] Note that lithium nitride may be formed and this produces ammonia when hydrolyzed, which contaminates the acetylene gas.