Do you remember crystal called dilithium from the world of Star Trek?. It was found on several planets, and was considered a very rare mineral with unique physical properties. This allowed Star Trek to perform interstellar travel. Its chemical symbol was Dt.
In real world Dilithium from the world of Star Trek is Li2 and it is a molecule consisting of two lithium atoms. Researches want to use lit(as LI6) with deuterium to produce fuel in the newly elaborated pulse propulsion. They have been working on it from a while now.