Admiral McLasthuman, I have those design specs you asked for.
... From the historical archives remaining from the original war, we have puzzled out how to create a galaxy wide explosion that will obliterate most ships, and all possible matter, that we or the AI mainframes, could use for bases, in a system. We have nicknamed these missiles 'nukes', as they will actually perform a task that humanity was worried about once upon a time. They will crack a planet in half.
When we designed these systems, we made sure to test them only in off wormhole systems, being basically unavailable to ourselves within our lifespans and to deny any 'good' systems to possible aggressors. We see how well THAT worked out with the Neinzul, but I digress. Thus, testing took centuries for final testing... and even then, we were unprepared for how well the matter detonators would transmit through the wormhole network when we finally used one in anger.
The following notes are the compiled documation of our 'nuclear' warhead testing, and... <static>
<static> ... 3 pounds of butter on his birthday cake. Apparently this was some inside joke amongst the development team which never made it into the specifciations, as the entire design crew laughed hysterically for days. Creation of the 'nuke' warheads always was an inside task, with the department (even under torture, we tried) never allowing any government source full access to the entire design of the warhead elements. In a way, developers of this warhead were like the masons of the old days. Apprentices eventually earned enough trust to be taught the methods, and then they were the protectors of the information.
Little things like this caught our attention, however, as the government tried to assemble the pieces. In the end though, this may have saved us. Being a memory only ingredient list, the AI could literally never get their hands on the assembly instructions to simply wipe us out. We didn't know that at the time.
Another item that these developers seemed to ask for in amazingly large quantities was quartzite. We have no idea why. We did find a lot of test rooms built of the stuff, sealed amazingly tightly with their veins aligned nearly perfectly. To us, these rooms appear utterly useless, however. Red Herring or masterstroke of genius, we may never know. Another... <static>
<static> ... as these firsts tests went off. Our instruments recorded what could only be described as a 'matter cascade'. I was forced to turn to fiction in my explanation to the powers that be as to what happened. I found the answer in a book described as 'Ender's Game'. A molecular disruption would occur, with atomic field disruption increasing as the energy from mass fed into the 'pulse wave' that would cascade out. The biggest problem with this was that to clear a system, it would require eventually tagging the planet. Detonating the nuke within a system's radius would nearly always hit a crystal or metal repository somewhere in the system. That would give it enough 'oomph' to reach the planet. Once there... the results were astounding. Nothing was left. The system was a broken shell of itself.
My aide was assigned to watch the reaction of the designers directly. He reported their faces were dead white during the after affects of the test. I don't, to this day, believe they expected to actually achieve their design goals. Half of them suicided within the week, and the rest started being heavily observed and were given ... <static>
<static> ... the AI mainframes. Heavily guarded by our own fleets, two of these missiles were brought in to the AI mainframe homeworlds, in an attempt to break the exo-gates they had created. Their local ships ignored the pulse! All of those good men and women, all that time and effort, broken. Our last ditch effort to break the AI and they'd anticipated us with ultra-dense materials.
The admiralty was in a dither, to put it mildly... <static>
<static> ... Hesperus III. It all came down to Hesperus III. We unleashed the nuke, god help us. Both of the AI mainframes were after the few remaining colonies behind the Hesperus III wormhole chokepoints. Those chokes were being supported by our manned fleets and over 20 colonies on the planet, and though we hadn't realized it was important, the largest civilian population center merely one jump away, over 18 billion people in our orbital command centers, on planet, on moons, you name it. It was the last place humans could call 'home' before being so completely disjointed and separated that manufacturing and knowledge wouldn't be lost.
All our marbles were in the Babylon system, with Hesperus as the gate. All the rest of our hubs were either destroyed or completely cut off, we were on our own. It doesn't forgive us for the choices we made that day, but I hope should a future race find our remains, it will add context to our foolishness. We created the largest nuke we'd ever built. We had prepared for the loss of Hesperus III, and hundreds of thousands of volunteers were willing to stay in system to 'Hold the Line'. To bait as much AI firepower into the system so in one strike we could try to buy ourselves enough breathing room to complete an exo-galactic transport of our own.
Big Bertha was prepped and left in an outlying system, nearly devoid of life should the unthinkable happen. Supply and rebuilder ships were prepared to jump to Hesperus III from Babylon. The plan worked perfectly. Huge antique golems supported by ships we'd never seen before built of crystal flagshipped a massive fleet of over 10,000 ships the AI had stolen designs from us for and designed themselves. Our fleets performed flawlessly, and baited the entire assault force through the system. Big Bertha was deployed.
On Babylon, we received images of the molecular disruption coming through the wormhole. It had traveled the space time rift on micro-meteors, persistant in space and due to the force of the initial blast, we can only assume it was able to reach even these minor components. Babylon was lost. Everything was lost.
Humanity struggled in the backwater... <static>
End record.