I would just call it AtomBlok.

That's block as in blockchain but without the c for visual aesthetic.

That's a far better name than the linguistic tongue twister that is æternity.

Use ATOM as the ticker.
Use www.atomblok.com as your website.
Use reddit.com/r/atomblok as your subreddit.

Sure, there's another coin out there called ATOM but they're not listed on any exchanges and have, literally, zero community. You won't have much resistance there.

Then once you've done that, design your logo as simply a circle within a square. The square represents the block, and the circle represents the atom.

Then you're good to go.