Trihydride tetrazine

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Most likely structure, negatively charged to account for the uneven number of hydrogen atoms.

Trihydride tetrazine, H5C2N4, is a chemical compound used in UNSC emergency thrusters. When mixed with hydrogen peroxide, an explosive force is produced that is large enough to radically alter the course of UNSC ships.[1]

The compound is used in D77-TC Pelicans to achieve "chemical thrust" during space flight.[2]