There was a really good post somewhere on Reddit a while back that I can't seem to find now that had a lot more details on the idea of a Nazi atom bomb, mostly

There was a really good post somewhere on Reddit a while back that I can't seem to find now that had a lot more details on the idea of a Nazi atom bomb, mostly political. I think the gist was that one of the key steps in a nuclear program at the WWII stage is the realization that an artificial nuclear explosion is practical, if difficult, and makes a very effective weapon of war. That also means that they understand the core physics concepts and have some idea of what building a bomb would involve. As I understand it, the Nazi regime never got to the point of even realizing that a bomb was a serious possibility. So naturally, they never devoted real resources to figuring out the details and how to go about actually building one. There's also the economic aspect - the initial development work was massively expensive, and even the other major WWII combatants who had an idea that a bomb was possible didn't think they would be able to devote enough resources to it to actually build one for that war. They may well have been right - even with the massive resources the US poured into the project, the war was still pretty close to being over before they had a bomb ready to drop.