Hierions are a family of fundamental particles that are unknown to human science. Hierions have long been used by the Huaoshy to make possible faster-than-light communication.
Some hierions form stable complexes by formation of hierion-hierion bonds. This allows molecule-like hierionic matter, but the size scale is much smaller than for conventional matter. A typical bond length in conventional molecules is about 0.15 nanometer, but the distance between adjacent/bound hierions is very much smaller: about 30 zeptometer. The small size of structures formed by hierions makes them useful as zeptoscale components of Huaoshy nanites.
Normally hierions are only found within spaces formed by compact dimensions. However, the Huaoshy long ago perfected hierion engineering and their advanced nanite technology makes use of hierionic matter.
Related topic: sedronic matter