The Omega molecule generator is a highly advanced piece of technology used by the Caeliar. The generator harnessed Omega molecules and was used to power the Caeliar's city ships. One such device on the city ship Axion was used at the end of the Borg Invasion of 2381 to lure the Borg armada to the Azure Nebula, where they were absorbed by the Caeliar, thus saving Earth and the Federation from imminent destruction. (Star Trek: Destiny Lost Souls)