A bit of a hard question as I cant seem to find anything on the topic and for some reason all the material I had previously is lost and forgot where I found it as I only recall the basic premise of the idea. I am curious if anyone would have some insight into this.
Basically, I was wondering about the technical ability to use compressed matter as a form of explosive. Similar to how an air tank could explode but more on the order that some mass could be compressed and then decompressed when needed. In a way it would be a bit like metallic hydrogen, provided it can be meta-stable, which is interesting because if so it could be used as a propulsive without any form of oxidizer since all you would need to do is just decompress the hydrogen. Something like that, but more easier to use as an explosive ordinance and that some also isn't hydrogen. Not that hydrogen couldnt be use in such a way, but the material I remember considering originally for the idea wasnt hydrogen. Just cant seem to remember what it was.