An intermix formula was the mathematical formula for combining matter and antimatter in such a way that it resulted in the balanced implosion required for power generation in a warp core. In 2266, the normal intermix formula used on the warp drive of Constitution-class starships required thirty minutes, or twenty two if hastened, to regenerate the core when it was initialized from a shut down state. The USS Enterprise became the first starship to test a theoretical new formula based on the relationship between time and antimatter. It involved a complete cold start of the core, without regeneration or heating of the antimatter. The crew were forced to use this theoretical formula when they attempted to avoid a crash landing to the Psi 2000 planet.