Atomics were the weapons of mass destruction used by the League of Nobles against Omnius. For years, the atomics were 'on the shelf' with in the League Worlds. Their value was primarily as a deterrent. However, after the independent robot Erasmus killed Manion Butler the Innocent, the Leauge used these weapons to erradicate the Omnius and all Thinking Machines on Earth.
Later, during Dune: The Battle of Corrin, the League would again use these weapons for The Great Purge. Each time a world was 'liberated' every human slave and Trustee were killed while erradicating the Thinking Machines on the planet.
Although not called "pulse-atomics" in Classic Dune, there is one use of atomics during the battle of the Plains of Arrakeen.
Also atomics were used during the destruction of Korona during Shaddam IV's Great Spice War
AtreidesDZ 20:14, 18 August 2008 (UTC)