Is there any scientific reason involving Caldonian Orogeny or the molecular structure of Ireland that would pit Northern Ireland with the UK instead of Ireland?

Wait, what are you asking?

I am really just wanting to know, if, from a standpoint involving the physical sciences there is a reason the six counties of Northern Ireland are part of the U.K. and not Ireland proper.

No – it’s completely based on history and the English takeover of Ireland in the 1700s. Nothing tomdo with geology at all.

Even on a molecular level?

Nope.

Molecular? No. Historical/political, yes. Is it still a good reason? Up to them to decide.

The molecular structure of Ireland?!?.
The border was created in 1920 when six of the nine counties of Ulster were given a parliament of their own. The partition line was man-made and aimed at enclosing the maximum area of land that could contain a Protestant majority.

I believe that current rational thought would hold that Ireland is a country, not a compound.

Conceivably, if Ireland was nothing but a vast lake of distilled water, it could then be a “country” comprised of uniform molecular structures.

If all of Ireland was somehow converted to pure fresh water, it could then be called something like Aqualand. In that case, Jason Momoa would become the prime minister.