I've seen a question about atheists who die.
"Amateur" atheists who wrestle on their own with their disbelief, but otherwise lead worthy lives, have a reasonable chance. The Lord is aware of pressures that may result in individual lack of faith.
However "professional" atheists have virtually no chance of heaven. These are people who do not keep their lack of belief private but actually advocate for others to lose their faith. Their lack of generosity toward another person's well being and salvation, unrepentant, face a "needle with no eye at all," rather than the surprise of just popping into a heaven that they did not believe in and attempted to drag others away from.