The looping technique at work here is an example of the "cross emission" technique which consists of emitting particles up to a certain amount of frames and then comping this sequence with itself from half-way in.
The system from which this loop was extracted was built on August 2nd, 2017 using After Effects and Trapcode TAO. The publication of its first iteration: https://xponentialdesign.tumblr.com/post/163707651796/dailies-trapcode-rubeum-gigas-quattuordecim
A later color version was archived on rodeoclub, a platform that has closed, it is now kept on opensea: https://opensea.io/item/base/0xd2997674dc355633c71640658cbe460ba8fa59a8/99
And this RGB iteration is a continuation from this long ongoing series and was exported with different emission seeds and with its central element made a flashing hazard. This is done trough the same initial source file. made available for patreon members: https://www.patreon.com/posts/hexagonum-after-157897267
720p-180frames-50fps-14.9mb