The mythological conception of God holds that God is basically like Zeus, Odin, or Apollo: having human-like personality traits but vastly more powerful than any human being could possibly be, and able to affect the world in ways that are basically magical. This is the conception of God denied by atheists who talk about “magical sky-beings” in or who use the trope, “we believe in one less God than Christians do.”
The metaphysical conception of God holds that God is the underlying, unifying principle that accounts for the intelligibility of the universe. God is why it is possible for us to understand anything at all about the world, including ourselves. This is the conception of God affirmed by metaphysical theologians like Aquinas, and denied by really quite radical atheists like Nietzsche or Camus.
One could reject the mythological conception and still take science seriously (and one might think that taking science seriously requires giving up the mythological conception) but it is difficult to see how one can give up on the metaphysical conception of God and still take science seriously. (Note: not impossible. Just that there is an intellectual puzzle to be solved here.) I don’t think it’s at all an accident that postmodern suspicions about science and truth begin with Nietzsche’s meditations on the death of God.
In any event, we might have better conversations around here if atheists are more clear if they are rejecting the mythological conception or the metaphysical conception.