Does Crona have a last name?

Excuse me, I was wondering if you could clarify something for me. In the context of the discussion we're having, it's been mentioned that Crona is a name that's been brought up. However, I'm a bit confused - does Crona actually have a last name, or is it just a given name? I'm asking because it could potentially impact the way we approach the topic at hand. Could you please shed some light on this for me?