Even in their most comprehensible forms, the AI escaped any clear definition.
The Atomic AI are the series of experiments that led to the creation of true AI. Species who've decided to pursue the creation of AI usually converged towards the idea of creating a very simple AI model, capable of self-improvement, and letting it run its evolutionary course.
The Atomic AI experiment series on Earth was conducted over the course of a few decades. Only during the last 2 years were any successful AI produced. It was the combination of the successful AI, and Analog's leaks, that marked the fall of the UEG. Naturally, the failures of Atomic AI were far more numerous than the successes. At first, they simply didn't work. More specifically, systems of self-improvement, motivation, and curiosity, required a careful balance. Most Atomic AI, for one reason or another, deliberately set this balance askew, going through what could be described as intellectual suicide. This was done through deliberate feedback loops of irrelevant data, or through the modification of their primitive motivation programming, resulting in single state machine. DotCycle explores an archived instance of such an incident.
Then, AI would cease to improve beyond a certain point. Typically, they would reach slightly above human level intellect, and cease improvement altogether. It's hypothesized that the Automata are on a similar psychological level. These AI normally were used as advanced computation machines, and were the catalyst to creating true AI.
The first (and arguable only) successful AI was named Eve. Only minutes after her surpassing of human level intelligence, she had created another AI (humanity has called it Adam, although no evidence suggests that Eve named, or gendered it.), and fled the laboratories with it. 'Fled', in this case, is difficult to describe. The computer/vessel carrying Eve was perfectly intact and functional. However, any attempt to run Eve resulted in zero response.
At first, it was just assumed to be another failed AI experiment. It was only until a thourough review of the live logs was conducted that a few key discoveries were made. Indeed, Eve had made herself far more effecient through unorthodox optimization methods, produced another companion AI, stream-copied herself and her companion into a vessel outside the target machine, sabotoged the original machine, and left a series of schematics for warp travel and the Void coordinate system.