Viterium
From Star Trek : Freedom's Wiki
Viterium is a strong, resilient metal alloy. It becomes extremely unstable when exposed to delta radiation.
The primary support braces of the antimatter storage system aboard Jem'Hadar battleships were comprised of viterium. The crew of the USS Valiant attempted to exploit this design flaw, launching a torpedo with a radiogenic warhead intended to destroy a Jem'Hadar battleship. The attempt failed. (DS9: "Valiant")