I think it's fair to consider the question in the context of what the asker is trying to find out.
It seems trivial to note that someone who doesn't believe in hell thinks that nobody will be there because it doesn't exist.
Likewise, it doesn't say a lot to wonder if someone acted in a manner that would lead to hell for even a believer, whether being a nonbeliever would change the outcome.
So the main thrust of the question is--do those who accept the idea of hell as real, think atheists wind up there that would not otherwise but for their atheism?
Obviously the answer is different according to whom you ask. One of the more interesting answers I got from a theist was from a good friend who identified as Lutheran, though I do not know how closely he adhered to specific doctrine. I happened to ask him his thoughts, because he knew that I was an atheist. His opinion was that the otherwise righteous atheists are not punished with direct suffering in the afterlife for non-belief--that instead they are forever denied the presence of God--and even then not so much as an imposed state, as that they exclude themselves by their nonbelief.
Seems something like Limbo--they don't get burned or lashed or receive cruelly ironic punishment, but they also don't get tickets to the afterparty.
(from "Road Movie to Berlin")