Atomics were the weapons of mass destruction used by the Army of the Jihad against Omnius, an evolution over atomics, specifically invented against the machines' gelcircuitry. For years, the atomics were 'on the shelf' with in the League Worlds. They were used for The Great Purge. Each time a world was 'liberated' every human slave and Trustee were killed while eradicating the Thinking Machines on the planet.