Intermix ratio

The intermix ratio was the ratio in which matter and antimatter were combined. A warp core is the most familiar device in which the intermix ratio was essential.

Following its expedited launch during the V'Ger incident, the warp core of the refitted USS Enterprise (NCC-1701) required new fuel equations to balance the intermix. The essential simulation of the flow sensors was bypassed resulting in an antimatter imbalance. 

In the 2364 Starfleet Academy entrance exam, one of the questions dealt with intermix ratios:
 * "The matter and antimatter tanks on a starship are nine-tenths depleted. Calculate the intermix ratio necessary to reach a starbase 100 light years away at warp factor 8."

This was a trick question as there was only one ratio with matter/antimatter: 1:1. 

In the same year, after the Shuttlecraft 13 crashed on Vagra II, the USS Enterprise (NCC-1701-D) was rushed to have warp drive operational. In the start-up sequence, prior to powering up the engine core and injecting reactants, the matter-antimatter injectors were primed to a ratio of 25:1. Minimal warp speeds were recommended, however Captain Jean-Luc Picard ordered warp 8. 

Jadzia Dax ordered the intermix be manually set to 0.01, prior to the warp chamber initialization, on the USS Defiant (2370) after it had been damaged by a cascade virus.