A containment chamber of Borg design that Seven of Nine builds in Voyager's cargo bay to hold and stabilise Omega molecules, and which Janeway uses to destroy them.
The harmonic resonance chamber appears in the Voyager episode The Omega Directive. Seven of Nine bases it on a design the Borg once used in a failed attempt to stabilise Omega, the molecule they revere as perfection.
After Voyager detects Omega, Janeway follows Starfleet's standing order to destroy it. The crew recovers molecules synthesised by a pre-warp civilisation's research station, and Seven adapts the chamber to contain them, hoping privately to save them for study.
Janeway instead orders the chamber used to break the molecules down. Shortly before it is ejected into space and destroyed with a torpedo, Seven sees the remaining molecules stabilise by themselves for a few seconds, an experience she compares to a glimpse of the divine.